Beyond Blue: New Horizons in Nitrides (Platform Grant Renewal)

Lead Research Organisation: University of Cambridge
Department Name: Materials Science & Metallurgy

Abstract

Our research is based on gallium nitride and its alloys, an amazing family of materials which can emit light over a wide range of colours - from the infra-red (IR) to the ultra-violet (UV). Already these materials are widely used in light emitting devices that are part of our everyday lives, perhaps most commonly in blue light emitting diodes (LEDs) and laser diodes (LDs). The LDs are at the heart of the blu-ray HD-DVD player, whilst the blue LEDs are combined with phosphors that emit other colours of light to produce white light. Such white LEDs are now very common in bicycle lights, torches and back-lighting for displays on portable electronic devices from mobile phones to tablet computers.

Cambridge and Manchester have been collaborating on materials for blue LEDs for over ten years. Our research has led to step changes in the understanding of the basic materials science and physics of the light emitting materials leading to improved LED efficiency. Also we have pioneered lower cost methods for the growth of the gallium nitride crystals used in LEDs which have been commercialised, and are currently being exploited by a UK company, Plessey, who are fabricating these devices at their UK factory in Plymouth. Whilst we aim to continue to improve both the performance and cost of our blue LED technology in collaboration with our industrial partners, enabling new applications, e.g. in health care systems, we are now looking beyond the blue LED to other applications of gallium nitride such as devices that will emit light in the green and UV parts of the spectrum. Currently nitride devices emitting in the green and UV have much lower efficiencies than blue LEDs, and this limitation prevents the full exploitation of the nitrides across the whole spectrum. Applying the successful Cambridge-Manchester approach of understanding the basic science underlying the materials' properties, and using this to drive device development, we aim to produce green LEDs for application in displays and in high quality white lighting for homes and offices. Perhaps even more significantly, UV LEDs could be a low-energy way to purify drinking water, which could save millions of lives in the developing worlds, and we are considering innovative approaches to the development of these devices.

Looking beyond LEDs, we will carry out research on LDs and even single photon sources. These latter devices, which emit one -and only one - photon on demand, are an enabling technology for quantum cryptography and quantum computation. We are already world leaders in the design and fabrication of blue single photon sources. The horizons we wish to explore are not necessarily new colours but devices with astounding new capabilities, such as the emission of pairs of entangled photons. Entanglement - which Albert Einstein referred to as "spooky action at a distance" - is a peculiar phenomenon by which changes made to one of the entangled pair of particles affect the other, even if the two are many miles apart. Entanglement can be used to achieve totally secure transfer of information. Gallium nitride can also be used in electronic devices, and so another emerging research theme at Cambridge and Manchester is the development of nitride transistors which will reduce the energy wasted as heat in high power applications such as computer power supplies, motor drives or power inverters of photovoltaic systems.

Overall, our research has the potential to provide clean water for millions, vastly reduce energy consumption and greenhouse gas emissions and to enable totally secure communications but there are many new applications on the horizon for GaN, and we hope that this platform grant will help us to keep the UK at the forefront of this outstanding developing technology.

Planned Impact

Our research will impact upon four core areas: society, the economy, people and knowledge.

*Society* Many aspects of our work will have significant impact on the health and wellbeing of society. Our research on light emitting diodes (LEDs) aims to increase the efficiency and reduce the cost of solid state lighting (SSL), which will lead to reduced energy bills for the UK public. The overall reduction in the cost of electricity could be over £2 billion per annum. Our work on green and amber LEDs will allow efficient SSL to have a spectrum more like sunlight, enhancing health and quality of life, and will also contribute to the development of high efficiency displays, further reducing greenhouse gas emissions. We will develop efficient, cheap deep-UV light sources, tuned to kill all bacteria and viruses, for water and air purification, potentially saving millions of lives in the third world, and enhancing health - for example through medical instrument sterilisation - in the UK. Our research on GaN structures for dose monitoring of X-ray and proton beams (collaborative project to be led by Hamilton (Manchester)) will improve the effectiveness of cancer therapies, saving lives.

*The economy* We will build upon our excellent track record of wealth creation by setting up and collaborating with a range of companies. We have set up two companies, CamGaN in 2010 and Intellec in 2011, to exploit our research on low-cost GaN LEDs grown on 6-inch Si. Plessey acquired these companies in 2012 and is now manufacturing low-cost LEDs in Plymouth, generating revenue and employment in the UK. We anticipate further opportunities to generate patents and/or set up further new companies based on unique devices we are developing, such as polarised blue single photon sources. Also we have successfully collaborated on LED reliability with Forge Europa, an SME in Cumbria, and its MD, Peter Barton, states that we have assisted the company to grow by over 100% in 3 years. We have also been collaborating with AIXTRON, based in Swavesey (Cambs) and Aachen, and its MD, Tony Pearce, states that our collaboration has helped them have sales of over £500 M over three years. Our development of UV light sources for water and air purification, lithography, and sterilisation of medical equipment will have economic impact by extending the product ranges of UK companies in the lighting supply chain. The economic impact of our research was recently highlighted in David Willets'' booklet Eight Great Technologies (2013, p.44) and in his Mountbatten Memorial Lecture in 2013.

*People and Knowledge* Members of our groups regularly take up positions in industry, transferring knowledge and skills. In recent years our PhD students and post-docs have been employed in the UK by AIXTRON, Plessey, Sharp, Forge Europa, Johnson Matthey and Toshiba. In the future, we will offer enhanced industry-led training for post-docs, so that they can contribute even more effectively in industry. In disseminating our research, we engage the public extensively. For example in March 2013, at the invitation of the EPSRC, our groups exhibited at the Big Bang Fair at the London ExCeL Centre. In June, we exhibited again on an EPSRC stand on "Advanced Materials" at The Times Cheltenham Science Festival for six days, a team effort involving both Manchester and Cambridge research students, post-docs and staff. We also exhibited at Jodrell Bank Live in which we stressed the energy saving theme of our work. Each of these science communication activities attracted thousands of visitors, including many school pupils. Our research has featured in the national press, on radio and TV. We anticipate that the research planned on our new Platform Grant will attract more media coverage and we aim to not only maintain our public engagement activities but to enhance them by exploiting new opportunities offered by social media.

Publications

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Angioni E (2016) A single emitting layer white OLED based on exciplex interface emission in Journal of Materials Chemistry C

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Blenkhorn WE (2018) Resonant photoluminescence studies of carrier localisation in c-plane InGaN/GaN quantum well structures. in Journal of physics. Condensed matter : an Institute of Physics journal

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Bruckbauer J (2016) Colour tuning in white hybrid inorganic/organic light-emitting diodes in Journal of Physics D: Applied Physics

 
Description Graphene.
A PDRA on this grant has found a new way to produce low-cost, high-quality large area graphene. This is a world first. At present, all the large-area graphene produced by others is of too low quality to be used in electronic devices, which is the major reason why graphene is not fulfilling its potential in this field. A patent on this was filed in 2015 and a new spin-out company formed, 2D Technologies Limited. The Directors are the PDRA, Simon Thomas, another EPSRC-funded PDRA, Ivor Guiney, and Prof Colin Humphreys. In July 2017 they set up another spin-out company, Paragraf. They have grown the graphene on gallium nitride, silicon and sapphire substrates, so far. They believe it has huge potential for electronic devices, energy generation (e.g.solar cells), etc. They completed raising seed funds of £2.64 million for Paragraf in October 2017. They were in the unusual position of being offered more funds than we had requested. So far, despite its huge potential, applications of graphene have been limited to the use of graphene flakes and powders in paint, tennis racquets, car tyres, etc. They believe their research may provide a major breakthrough and lead to real electronic device applications of graphene. Paragraf moved into premises near Cambridge in January 2018, equipment was delivered in February 2018, and already eight members of staff had been employed. Recently a joint Development programme has been established with Verditek, a solar cell company, to develop the first graphene based solar panel.

Earthquake prediction.
Research student, Bertrand Rouet-Leduc has developed a machine learning program under this Platform Grant for optimizing the performance of GaN-based LEDs. This is a world first. Los Alamos National Laboratory in New Mexico were very interested in seeing if his machine learning methods could be applied to predicting earthquakes. Bertrand was seconded to them and, remarkably, he was able to analyse acoustic signals from a laboratory generated earthquake to spot the tell-tale signs of this earthquake in advance. Another world first. The paper was published in Geophysical Research Letters in 2017 and received huge worldwide publicity, with articles in the national daily newspapers of India, China, Singapore, Philippines, Japan, Mexico, Canada, USA, etc . In the UK the work featured in most of the main daily papers. Colin Humphreys was interviewed by the BBC, BBC World Service, etc.The machine learning has spotted an entirely new signal from the laboratory earthquake that geologists had previously dismissed as noise. This can give a one-week warning of an earthquake: the existing warning time is only 10 seconds. So this could save many lives.The next step is to test the machine learning program on real earthquakes, and this is currently being done on an earthquake zone in Canada. It is also believed that the techniques we are using could be used to predict earthquake-like failures in other materials, such as turbines in aircraft and power stations. The flexibility provided by our Platform Grant has enabled us to transfer a world first in GaN science to earthquake science and to set the stage for potentially life-saving advances in earthquake prediction.

Cubic GaN.
All GaN devices (LEDs, lasers, electronic devices) are made from GaN having an hexagonal structure. GaN with a cubic structure is not stable, so is difficult to grow, but theoretically it has some major advantages over hexagonal GaN. All previous attempts by others worldwide to grow single phase cubic GaN by MOVPE have failed. However, we have succeeded in growing 100% pure phase cubic GaN. This is a world first. This research promises to make even more efficient LEDs, particularly for green light emission, and solve the "green-gap" problem. This research on cubic GaN has led to two Innovate UK grants and a cubic GaN spin-out company, Kubos, has recently resulted.

Porous GaN
Prof Rachel Oliver and her team have developed a new method for the fabrication of sub-surface porous gallium nitride which requires no external patterning steps. It leaves the wafer surface smooth, clean and ready for further epitaxy. The sub-surface porous layers can be processed with a range of thicknesses and porosities and different pore morphologies. This is a potential enabling technology for a range of GaN-based devices. So far, the overgrowth of light emitting diodes on highly reflective porous GaN mirrors has been demonstrated, and the resulting devices show improved extraction efficiency and enhanced droop performance. The technology has been patented and a spin out company has been set up. The spinout company, Poro Technologies has raised £1.5 M in seed funding and has established a pilot plant and R&D facility in Cmabridgeshire.

The platform grant underpins all of the nitride and related research at Cambridge, so these key findings are merely examples of the broad selection of successful research it supports.
Exploitation Route Our findings on graphene are being taken forward by our spin-out company, Paragraf (www.Paragraf.com). Our findings on machine learning for earthquake prediction are being taken forward by Los Alamos National Laboratory, and no doubt by others. Our findings on cubic GaN were taken forward by an Innovate UK grant with Anvil semiconductors and Plessey from October 2015 to December 2016 (gtr.rcuk.ac.uk/projects?ref=101483), followed by a new Innovate UK grant to us in 2017 (with the EPSRC funding the Cambridge University research), and a new spin-out company has resulted from this. Our findings on porous GaN resulted in the finding of Poro Technologies Ltd, which has recently won Innovate UK funding, jointly with Plessey Semiconductors for Development of MicroLED technologies.
Sectors Aerospace, Defence and Marine,Chemicals,Digital/Communication/Information Technologies (including Software),Electronics,Energy,Environment,Healthcare,Manufacturing, including Industrial Biotechology

URL https://www.technologyreview.com/s/603785/machine-learning-algorithm-predicts-laboratory-earthquakes
 
Description Graphene. Based on findings on graphene, a new spin-out company formed, 2D Technologies Limited. The Directors are the PDRA, Simon Thomas, another EPSRC-funded PDRA, Ivor Guiney, and Prof Colin Humphreys. In July 2017 they set up another spin-out company, Paragraf. They completed raising seed funds of £2.64 million for Paragraf in October 2017. They were in the unusual position of being offered more funds than they had requested. Paragraf moved into premises near Cambridge in January 2018, equipment was delivered in February 2018, and already eight members of staff had been employed. Recently a joint Development programme has been established with Verditek, a solar cell company, to develop the first graphene based solar panel. Earthquake prediction. Based on research on earthquake prediction, Colin Humphreys was interviewed by the BBC, BBC World Service, etc. Cubic GaN. The research on cubic GaN has led to two Innovate UK grants and a cubic GaN spin-out company, Kubos, has recently resulted. Porous GaN Our porous GaN technology has been patented and a spin out company has been set up. The spinout company, Poro Technologies is going from strength to strength and has recently raised $20M in series A funding. It has established a pilot plant and R&D facility in Cambridgeshire and has created 22 jobs in the UK.
First Year Of Impact 2017
Sector Chemicals,Construction,Digital/Communication/Information Technologies (including Software),Electronics,Energy,Environment,Healthcare,Manufacturing, including Industrial Biotechology
Impact Types Societal,Economic

 
Description Fundamental studies of zincblende nitride structures for optoelectronic applications
Amount £493,481 (GBP)
Funding ID EP/R01146X/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 02/2018 
End 01/2021
 
Description Porous InGaN for Red LEDs (PIRL)
Amount £349,961 (GBP)
Funding ID 107470 
Organisation Innovate UK 
Sector Public
Country United Kingdom
Start 03/2021 
End 03/2023
 
Description Simulation software for modelling nitride-based quantum light sources
Amount £88,759 (GBP)
Funding ID EP/R04502X/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 03/2018 
End 02/2019
 
Title Research data supporting "Alloy Segregation at Stacking Faults in Zincblende GaN Heterostructures" 
Description  
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
URL https://www.repository.cam.ac.uk/handle/1810/311238
 
Title Research data supporting "Combined SEM-CL and STEM investigation of green InGaN Quantum Wells" 
Description revised fig. 1:shows the 5 µm × 5 µm AFM scans of the MQW samples revealing the surface morphology. The QW growth temperature (T), rms roughness (R) and image height (H) are stated on the image. H is the difference in height between the highest and lowest pixels in the image fig. 2: The density of dislocations against QW growth temperatures for the MQW samples. Fig. 2 data: data set for Fig. 2 fig. 3: CL images of the MQW sample taken from the surface. The QW growth temperature (T) is stated on the image. fig. 4: (a) CL image taken on the sample grown at 698 °C and (b) SE image taken on the same position of (a). Example dislocations are enclosed in the red circles and an example dark patch is highlighted by the yellow curve. revised fig. 5: (a) The peak emission amplitude and The peak emission amplitude and (b) the peak emission wavelength obtained from a CL line scan performed on the sample grown at 698 °C across a dark patch boundary. Two fitting examples of the dark patch and the bright area are show in (c) and (d), respectively. The dark patch boundary is marked by the green lines. There are two large blue-shift peaks within the dark patch which are related with nearby dislocations. Disregarding the regions near TDs, the average emission amplitudes and wavelengths of the dark patch and the bright area are indicated by red dotted lines. Fig. 5 data: data set for Fig. 5 fig. 6: (a) The CL image taken in step 2. The line-scan position is highlighted by the yellow line. (b) The AFM profile corresponding to the line-scan position extracted from the AFM image taken in step 4. (c) The overview STEM HAADF image taken in step 6. Dislocations in (c) are matching with the dislocation pits found in (b). The dark patch boundary found in step 3 is marked by thicker Pt deposition on the sample surface, which is highlighted by the green arrow. Fig. 6 profile: data set for Fig. 6(b) fig. 7: STEM HAADF images showing the MQW structure of the dark patch and the bright area in the sample grown at 698 °C. The bright lines show the positions of QWs. GWWFs are marked in red doted boxes. revised fig. 8 The average densities of GWWFs plotted against the QW growth temperatures Fig. 8 data: data set for Fig. 8 
Type Of Material Database/Collection of data 
Year Produced 2021 
Provided To Others? Yes  
URL https://www.repository.cam.ac.uk/handle/1810/316805
 
Title Research data supporting "Defect structures in (001) zincblende GaN/3C-SiC nucleation layers" 
Description The data file "facet angle AFM" contains the full datasets of facet angles measured by AFM of a nominally 3 nm-thick annealed GaN NL grown on 3C-SiC. The individual islands have been approached by front of the AFM tip along the fast scan direction, which was along [110] (along the short axis of the islands). Linescans have been taken parallel to fast scan direction in direction of the approaching tip. Angles have been measured between the facets and the surrounding surface. To determine the facet angle of the other site of the islands, the sample has been rotated by 180° prior to another AFM measurement. 
Type Of Material Database/Collection of data 
Year Produced 2021 
Provided To Others? Yes  
URL https://www.repository.cam.ac.uk/handle/1810/321510
 
Title Research data supporting "Effect of growth temperature and V/III-ratio on the surface morphology of MOVPE-grown cubic zincblende GaN" 
Description Figure 1: XRD intensity profile through the 1-103wz and 113zb reflections for the samples grown on a 4° miscut substrate at 875°C and a V/III-ratio of 76 (a), and 1200 (b). Figure 4: Feature sizes in (a) [110] and (b) [1-10] directions extracted from 2D-FFT of AFM height data of zb-GaN epilayers grown at different growth temperatures and a constant V/III-ratio of 76. (c) Variation of the aspect ratio of surface features with growth temperature. (d) Variation of root mean square surface roughness with growth temperature. Figure 5: Zb-GaN content determined by XRD as a function of the GaN epilayer growth temperature. Figure 8: Feature sizes in (a) [110] and (b) [1-10] directions extracted from 2D-FFT of AFM height data of the zb-GaN epilayers grown at different V/III-ratios and a constant growth temperature of 875 °C. (c) Variation of aspect ratio of surface features with V/III ratio. For (a) to (c), there are no data points for the sample grown at a V/III-ratio of 15, as it was not possible to extract feature sizes using the same 2D-FFT method as for other sample in the series. (d) Variation of root mean square surface roughness with V/III-ratio. The labels i, ii and iii indicate the proposed growth regimes. Figure 11: Relative intensities of the zb-GaN XRD peaks for samples in the V/III-ratio series at a constant growth temperature of 875 °C. 
Type Of Material Database/Collection of data 
Year Produced 2018 
Provided To Others? Yes  
 
Title Research data supporting "Influence of AlxGa1-xN nucleation layers on MOVPE-grown zincblende GaN epilayers on 3C-SiC/Si(001)" 
Description Fig 2 - XPS - 00% from growth (C7319A after etching).xlsx Fig 2 - XPS - 25% from growth (C7321A after etching).xlsx Fig 2 - XPS - 50% from growth (C7323A after etching).xlsx Fig 2 - XPS - 75% from growth (C7322A after etching).xlsx Fig 2 - XPS - 100% from growth (C7320A after etching).xlsx Fig 2 - XPS analysis.xlsx XPS raw data and analysis for Figure 2 Figure 3_AFM_annealed.zip AFM raw data of annealed samples for figure 3 Figure 3_AFM_asgrown.zip AFM raw data of as-grown samples for figure 3 Figure 4_AFM roughness and featuresize.zip AFM RMS roughness and featuresize analysis of as-grown and annealed nucleation layers Figure 5_XRD.zip XRD raw data of as-grown AlGaN nucleation layers Figure 6_strain.zip Strain analysis of the nucleation layers Figure 7_AFM_GaN epilayer.zip AFM raw data of GaN epilayers Figure 8_AFM roughness and featuresize.zip AFM RMS roughness and featuresize analysis of GaN epilayers Figure 9.zip XRD omega FWHM and zincblende content of GaN epilayers Figure 10.zip XRD texture maps raw data of GaN epilayers on AlGaN nucleation layers with varying Al content 
Type Of Material Database/Collection of data 
Year Produced 2022 
Provided To Others? Yes  
URL https://www.repository.cam.ac.uk/handle/1810/332888
 
Title Research data supporting "Multimicroscopy of cross-section zincblende GaN LED heterostructure" 
Description Fig. 2(a): the SEM-CL image of the cross-section FIB specimen. Fig. 2(c): Data set of the the mean CL spectrum extracted from CL-Data-withoutfeature.bin in .csv format Fig. 3(a): data set of the mean spectrum taken near the SiC/GaN interface of the cross-section FIB specimen extracted from CL-Data-withoutfeature.bin in .csv format Fig. 3(b): data set of the mean spectrum taken just below the InxGa1-xN MQW of the cross-section FIB specimen extracted from CL-Data-withoutfeature.bin in .csv format Fig. 3(c): data set of the mean spectrum taken at the InxGa1-xN MQW layer of the cross-section FIB specimen extracted from CL-Data-withoutfeature.bin in .csv format Fig. 4(a): data set of the Gaussian fitted peak emission energy map for GaN NBE at around 3.27 eV of the cross-section FIB specimen, extracted from CL-Data-withoutfeature.bin in .csv format Fig. 4(b): data set of the Gaussian fitted peak emission energy map for QW emissions at around 2.71 eV of the cross-section FIB specimen, extracted from CL-Data-withoutfeature.bin in .csv format Fig. 4(c): data set of the spectrum of a selected location where the Gaussian fit does not accurately depict the behaviour of the MQW, extracted from CL-Data-withoutfeature.bin in .csv format Fig. 5(a): the HAADF STEM image of the cross-section FIB specimen including a protruding MQW structure, named feature A. Fig. 5(insert): the panchromatic CL image of the cross-section FIB specimen corresponding to Fig. 5(a),extracted from CL-Data-with feature.bin Fig. 5(b): data set of the spectrum of feature A, extracted from CL-Data-with feature.bin in .csv format Fig. 5(c): data set of the spectrum of the flat MQW area in Fig. 5(a), extracted from CL-Data-with feature.bin in .csv format Fig. 6(1): the diffraction patterns taken from GaN film Fig. 6(2): the diffraction patterns taken from feature A Fig. 6(3): the diffraction patterns taken from SFs below feature A Fig. 6(4): the diffraction patterns taken from the boundary of feature A Fig. 7(a): the HAADF STEM image of feature A Fig. 8: Dataset of the EDS map of Indium taken at feature A in .ser format. The raw data can be opened with the open source software ImageJ and other electron microscopy software packages. CL-Data-with feature.bin: Raw data of the CL hyperspectral image in binary format. The data can be opened with the open source LumiSpy Python library CL-Data-withoutfeature.bin: Raw data of the CL hyperspectral image in binary format. The data can be opened with the open source LumiSpy Python library 
Type Of Material Database/Collection of data 
Year Produced 2021 
Provided To Others? Yes  
URL https://www.repository.cam.ac.uk/handle/1810/330704
 
Title Research data supporting "X-ray diffraction analysis of cubic zincblende III-nitrides" 
Description Figure 6: XRD peak width of an optimized zincblende GaN sample displayed in a traditional Williamson-Hall plot with fits for Lorentzian (n = 1) and Gaussian shape peaks (n = 2). Figure 7: Extrapolated peak width ß_hkl ×|Q_hkl| in reciprocal space as a function of polar angle Chi and scattering vector magnitude |Q_hkl| estimated from a series of skew-symmetric ?-scans. Figure 8: Decrease of the XRD ?-linewidth (FWHM) of the 002 reflection with increasing film thickness for oriented zincblende GaN grown on 3C-SiC at Cambridge University. Figure 9: An example for a XRD wafer bow analysis of a 4'' 3C-SiC/Si template showing the shift of the maximum of ?-scans at different positions on the wafer. 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? Yes  
 
Description Aixtron AFM collaboration 
Organisation Aixtron Limited
Country United Kingdom 
Sector Private 
PI Contribution Atomic force microscopy studies of 2D materials
Collaborator Contribution Provision of materials, data interpretation
Impact Ongoing
Start Year 2019
 
Description Anvil Semiconductors 
Organisation Anvil Semiconductors
Country United Kingdom 
Sector Private 
PI Contribution We have grown cubic Gan on Anvil supplied cubic SiC on large area silicon substrates. This is a world first.
Collaborator Contribution They have supplied the cubic SiC on Si substrates, of first 100 mm and then 150 mm diameter.
Impact A world first in the growth of pure phase cubic GaN on 150 mm substrates.
Start Year 2015
 
Description Forge Europa (International Headquarters 
Organisation Forge Europa
Country United Kingdom 
Sector Private 
PI Contribution Expertise. Solving a major problem with the reliability of some Forge Europa LEDs
Collaborator Contribution Advice. Testing. Market forecasts.
Impact Improved reliability and lifetimes of Forge Europa LED based products.
 
Description IQE Collaboration 
Organisation IQE Europe Limited
Country United Kingdom 
Sector Private 
PI Contribution Electrochemical etching and characterisation of distributed Bragg reflectors
Collaborator Contribution Provision of materials for etching, overgrowth, characterisation
Impact Ongoing work.
Start Year 2019
 
Description Investigating opportunities for commercialization of porous nitrides 
Organisation Elucidare
Country United Kingdom 
Sector Private 
PI Contribution We are working with Elucidare on an EPSRC Impact Acceleration Account Follow-On Fund project to explore commercialisation opportunities for the porous GaN technologies arising from this project. We are providing access to a range of research data to facilitate this.
Collaborator Contribution Elucidare are using our research data to liaise with a range of companies internationally to explore commercialisation opportunities for our technology.
Impact No specific impacts yet.
Start Year 2018
 
Description Plessey collaboration 
Organisation Plessey Semiconductors Ltd
Country United Kingdom 
Sector Private 
PI Contribution We developed a new low-cost high-efficiency method for making GaN LEDs. we set up two companies which Plessey acquired. Plessey also hired 3 of my post-docs to transfer the technology and as permanent hirings. We continue to collaborate with Plessey, providing them with advice. We also provided them with two growers for a period of three months when their main grower left in 2016.
Collaborator Contribution Plessey process LED structures that we grow and we exchange information. The processing of our wafers is very important for our research.
Impact Plessey are manufacturing GaN-on-Si LEDs at Plymouth based on our technology. This is the first and only manufacturing of GaN LEDs in the UK. Plessey had the first commercially available GaN LEDs on large area Si in the world, based on our Cambridge technology, funded by the EPSRC. Plessey raised £30 million from the Deutsche Bank and £30 million from other investors in 2015 to expand their GaN-on-Si LED manufacturing. The are employing over 100 people in Plymouth in LED manufacturing. They are manufacturing millions of LEDs per year. Materials Science, Physics, Chemistry, Electronics.
Start Year 2010
 
Description Porotech collaboration 
Organisation Poro Technologies Ltd
Country United Kingdom 
Sector Private 
PI Contribution We are collaborating with Poro Technologies on a range of projects including the development of porosification technologies for strain and wafer control in GaN light-emitting devices. Our contributions include the modelling of the impact of porosification processes on strain and wafer bow in GaN structures and devices using finite element methods and the measurement of the structure and properties of porosified materials.
Collaborator Contribution Poro Technologies have provided materials before and after porosification for microstructural characterisation and comparison with our models.
Impact The work is ongoing, but has resulted in the award of an InnovateUK grant. We are unable to provide full details of this since we are awaiting the offer letter.
Start Year 2020
 
Description Quantopticon collaboration 
Organisation Quantopticon Ltd
Country United Kingdom 
Sector Private 
PI Contribution Quantopticon are a startup company developing software to predict the performance of quantum systems. Based on the outputs of this grant, they have asked us to partner with them on a new InnovateUK grant. We have been involved so far in writing the grant proposal which has recently been funded, and will in future provide data to Quantopticon as an input to their model to test its effectiveness.
Collaborator Contribution Quantopticon are leading the InnovateUK project mentioned above.
Impact New funding.
Start Year 2017
 
Description St Gobain- Lumilog 
Organisation Saint-Gobain Lumilog
Country France 
Sector Private 
PI Contribution Characterisation of samples to investigate leakage pathways in GaN electronics
Collaborator Contribution Provision of samples for characterisation
Impact A report will be made to the relevant industry
Start Year 2020
 
Title METHOD FOR POROSIFYING A MATERIAL AND SEMICONDUCTOR STRUCTURE 
Description A method for porosifying a Ill-nitride material in a semiconductor structure is provided, the semiconductor structure comprising a sub-surface structure of a first Ill-nitride material, having a charge carrier density greater than 5 x 1017 cm-3, beneath a surface layer of a second Ill-nitride material, having a charge carrier density of between 1 x 1014 cm-3 and 1 x 1017 cm-3. The method comprises the steps of exposing the surface layer to an electrolyte, and applying a potential difference between the first Ill-nitride material and the electrolyte, so that the sub-surface structure is porosified by electrochemical etching, while the surface layer is not porosified. A semiconductor structure and uses thereof are further provided. 
IP Reference WO2019063957 
Protection Patent application published
Year Protection Granted 2019
Licensed Yes
Impact Patent has been licenced to Poro Technologies Ltd, a University of Cambridge Spinout Company which currently has 3 employees and plans to hae 8 by the end of the year. Poro Technologies are setting up a pilot plant in Cambridge.
 
Title X-ray modelling code for porous GaN DBRs 
Description A modelling code to simulate X-ray diffraction data from porous gallium nitride distributed Bragg reflectors. 
Type Of Technology Software 
Year Produced 2019 
Impact Very recently released open access software. No known impacts yet. 
URL https://aip.scitation.org/doi/suppl/10.1063/1.5134143
 
Company Name 2D Technologies Limited 
Description 2D Technologies was set up to exploit a new way of growing large-area, high-quality graphene and to combine this with GaN in devices. The Directors are Professor Sir Colin Humphreys and two of his post-docs. The research for this was performed as a blue skies project on my Platform Grant Renewal, "Beyond Blue". We are currently seeking seed funding, which we believe we have just achieved (February 2017). 
Year Established 2015 
Impact One patent has been filed to date, in the UK, Internationally and in Taiwan. We believe we have just achieved seed funding for this company from a range of investors (February 2017). We believe we have achieved our goal of low-cost, large-area, high-quality graphene, which no one else has achieved. This could be important for a wide range of devices and would make graphene really useful.
Website http://www.endole.co.uk/company/09889431/2d-technologies-limited
 
Company Name Paragraf 
Description Paragraf was formed from feasibility studies made by two of Humphreys PDRAs, Simon Thomas and Ivor Guiney, employed on his EPSRC grants, and developed on his EPSRC IAA Follow-on Fund. Paragraf is exploiting a new way of making large-area graphene and other 2D materials for applications in electronic devices, energy generation (e.g.solar cells), sensors, etc. Humphreys is the Company Chairman and a Non-Executive Director. The company moved into premises in Somersham, Cambs, in February 2018 and is already employing 16 people (as at February 2019). It has filed 8 patents. It is about to launch its first product. 
Year Established 2017 
Impact Paragraf has been moving rapidly. It obtained seed funding of £2.64 million in October 2017, moved into premises near Cambridge in January 2018, took delivery of equipment in February 2018 and is already employing 8 members of staff. It plans to be manufacturing large-area (8-inch) graphene by the end of March 2018, and then producing prototype device structures. Recently a Joint Development Programme with the solar cell company Verditek was agreed to develop the first Graphene based solar panel.
Website http://paragraf.com
 
Company Name PORO TECHNOLOGIES LTD 
Description Porotech has six FTEs and two PTEs. In November 2019 it closed a GBP1,500,000 seed round investment [E8]. Formed in 2018 to commercialise Cambridge research on porous GaN, Porotech is developing the means of producing low-cost porous GaN products and technologies such as LEDs, lasers, solar cells, power electronics, and sensors with performance properties that significantly exceed those of existing technologies. LEDs manufactured using porous GaN substrates, for example, were "some 25% more energy efficient than standard LEDs" ( see e.g. https://compoundsemiconductor.net/article/110968/British_GaN_Spin-out_Porotech_Raises_%C2%A315m). Porotech closed a £1.5M pre-seed investment round in November 2018, and in June 2020 opened an R&D facility. In 2020, it achieved commercial revenue of £11k, and in 2021 of £340k. It has raised £19M of investment, including substantial inward investment, and has created 22 new UK jobs. 
Year Established 2018 
Impact • November 2018: £1.5M pre-seed funding raised • June 2020: Opened R&D facility and pilot plant in South Cambridgeshire • July 2020: completed first commercial order, supplying Osram Opto, the world's second largest optoelectronics company, achieving a revenue of EUR12,000. • November 2020: product launch of the world's first commercial native red LED epiwafer for micro-LED applications. • December 2020: Winners of International "Win the Future" Venture Contest in Suzhou, China. • June 2021: Raised £3M in seed funding round. • July 2021: Announced first commercial partnership, with Jade Bird Display (JBD) in China, a leader in micro-LED display technology. • October 2021: Announced world's first native red InGaN microdisplay • 2021: Annual commercial revenue of £340k. • February 2022: Completed series A Funding round of ca. £14.5M.
Website https://www.porotech.co.uk/
 
Description Alumni festival talk (Secrets and Lights) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact An interactive talk was delivered at the Cambridge Alumni Festival about single photon sources and their application in quantum cryptography
Year(s) Of Engagement Activity 2016
URL https://www.alumni.cam.ac.uk/events/alumni-festival-2016/secrets-and-lights
 
Description Cambridge Centre for Gallium Nitride Outreach Apps 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Two android apps which provide an interactive way for users to learn about light emitting diodes.
Year(s) Of Engagement Activity 2018,2019,2020
URL https://www.gan.msm.cam.ac.uk/resources/our-apps
 
Description Cambridge ICE - Little Lights with Big Ideas 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact This talk was delivered as part of an online adult education programme provide by the Cambridge Insitute of Continuing Education, intended to provide free enrichment activities for the general public during the pandemic.
Year(s) Of Engagement Activity 2020
 
Description Cambridge Science Festival - Drop in workshops 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Two workshops were presented within a dropin session. These two workshops focussed on energy efficient LEDs and cooling electronics using diamond repectively.
Year(s) Of Engagement Activity 2019
 
Description Cambridge Science Festival 2015 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Over 100 people attended an interactive talk which sparked questions and discussions afterwards. The science festival had positive feedback that attendees enjoyed the event and we have been asked to put on a larger event in 2016.
Year(s) Of Engagement Activity 2015
URL http://www.sciencefestival.cam.ac.uk/about/past-festivals/2015-cambridge-science-festival
 
Description Cambridge Science Festval - Crazy about Colour 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact In each year about 20 children and their families participated in a workshop about the colour of LEDs and how coloured light is used.
Year(s) Of Engagement Activity 2018,2019
 
Description Cambridge Science Festval - Inside an LED 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Over 100 people attended a talk on the science underlying engery efficient LED light bulbs.
Year(s) Of Engagement Activity 2019
 
Description Cheltenham Science Festival 2019: Communication using Liht 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Three separate school groups attended a workshop on light-based communications, covering fibre optics, LiFi and single photon sources.
Year(s) Of Engagement Activity 2019
 
Description Chesterton Science Club (Communication using Light) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact An interactive talk on "Communication using Light" was delivered to the Chesterton Community College Science Club, incorporating elements on LiFi using LEDs and quantum communication using single photon sources.
Year(s) Of Engagement Activity 2016
 
Description Communication using light - Hatchend School 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact A workshop on the uses of light in communications, delviered to multiple classes in thee 14-16 age group and their teachers.
Year(s) Of Engagement Activity 2018
 
Description Crazy about Colour (Grove School and Stephen Perse Pre Prep) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact A workshop about LEDs and colour for KS1 children delivered to multiple classes across two schools in Cambridge on the same day.
Year(s) Of Engagement Activity 2018
 
Description Crystal structure activities 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Schools
Results and Impact A set of downloadable activities to allow users to build their own crystal structures and understand the properties of crystals.
Year(s) Of Engagement Activity 2018
URL https://www.gan.msm.cam.ac.uk/resources/crystalmodels
 
Description Discover materials winter talk 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact A short talk called "Inside an LED" was delivered to school students across the country as part of an online workshop.
Year(s) Of Engagement Activity 2020
URL https://www.youtube.com/watch?v=-FOOnxwAQgQ&t=81s
 
Description EYFS LED session 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact A workshop on light and electricity was held for early years foundation stage children at a local school. The teacher provided feedback that this sparked discussion of related topics. We are planning to reach more children in this age group and in key stage 1 with a larger similar event at the Cambridge Science Festival based on this trial run.
Year(s) Of Engagement Activity 2016
 
Description EYFS and KS1 workshops at Cambridge Science Festival 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact A series of workshops on light and electricity was held for early years foundation stage and key stage 1 children as part of the Cambridge Science Festival. This sparked discussion with the children's parents also. This series of workshops will be repeated at Cambridge Science Festival this year and in local schools.
Year(s) Of Engagement Activity 2016
 
Description Inside an LED - Harrow School 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact A lecture at Harrow school, to which multiple other local schools were also invited. Teachers from across the Rugby Group of public schools also attended.
Year(s) Of Engagement Activity 2018
 
Description Inside an LED - virtual Headstart course lecture 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact This lecture was part of a course provided for sixth form students considering taking STEMM degrees at Universit to provide them with an insight into a broader range of STEMM subjects.
Year(s) Of Engagement Activity 2020
URL https://www.youtube.com/watch?v=W1FFh--7d9I&t=2s
 
Description Little Light Sources With Big Ideas (#RobinSTEM) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact A short talk on quantum dots and single photon sources as part of the Robinson College Women in Science Festival, which I organise.
Year(s) Of Engagement Activity 2018
URL https://www.robinson.cam.ac.uk/news/women-stem-festival-2018
 
Description Lots and Lots of Light Bulbs (Grove School) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact An EYFS workshop on light and energy delivered to two classes at the Grove School.
Year(s) Of Engagement Activity 2018
 
Description Lots and Lots of Light Bulbs, Virtual Workshop, Cambridge festival 2021 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact This online workshop for children in key stage 1 consisted of short videos (available here: https://www.msm.cam.ac.uk/bulbs) each containing an explanation of a key concept about how light-emitting III-V materials can help achieve energy savings and a fun activity which participants could do at home. We also mailed out activity kits to participants and ran an online live online Q&A to support the asynchronous video-based activities. The video workshop was watched by hundreds of people and is currently being adapted for use in primary schools. This workshop is a key example of how we have adapted our approach to outreach for online engagement during the pandemic. (Live versions of this workshop have also been delivered at multiple primary schools, some of which are described below).
Year(s) Of Engagement Activity 2021
URL https://www.msm.cam.ac.uk/bulbs
 
Description Making Materials Matter 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Plenary talk at a workshop for teachers
Year(s) Of Engagement Activity 2018
URL https://www.oxfordandcambridgeoutreach.co.uk/events/making-materials-matter-2018-tea
 
Description RealSci Nano - Twitter curation and podcast 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Rachel Oliver curated the @realscinano twitter account for a week, describing her research on nitride materials at the nanoscale and taking questions from the general public. She was interviewed for an accompanying podcast.
Year(s) Of Engagement Activity 2019
URL https://www.realscientistsnano.org/rachel-oliver
 
Description Researcher profiles website 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Schools
Results and Impact A website has been set up with career profiles for members of the Cambridge Gallium Nitride Centre as a resource for school and University students considering a career in research.
Year(s) Of Engagement Activity 2016,2017
URL http://www.gan.msm.cam.ac.uk/resources/profiles
 
Description Robinson College Women in Science Festival Talk (Little light sources with big ideas) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact As part of the Robinson College Women in Science Festival, an interactive talk was delivered on single photon sources.
Year(s) Of Engagement Activity 2016
 
Description Robinson Science Residential 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Approximately 40 sixth formers took part in a 2 day even at Robinson College to which I contributed a talk, tutorial content and a practical session. Robinson reported increased student applications in related subject areas.
Year(s) Of Engagement Activity 2015
URL https://www.robinson.cam.ac.uk/access-and-outreach
 
Description Robinson Women in Science Festivale 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Over 120 female sixth formers took part in a day festival aimed at encouraging participation in the Physical Sciences. In addition to organising the day, I gave a presentation on my research, chaired a student talk session and organised a practical session. Feedback from the sixth formers was very positive, several have been influenced to apply to study science at University and a second event is being organised.
Year(s) Of Engagement Activity 2015
URL https://www.robinson.cam.ac.uk/access-and-outreach
 
Description Science festival talk (How Can GaN Change Your Life?) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact An interactive talk was delivered to a large audience at the Cambridge Science Festival, outlinging a number of different uses for Gallium Nitride from lighting to quantum communications.
Year(s) Of Engagement Activity 2016
 
Description Secrets and Lights - Cafe Scientifique Bishops Stortford 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact A lecture on single photon sources and quantum cryptography
Year(s) Of Engagement Activity 2018
 
Description Secrets and Lights, Online Lecture, Cambridge festival 2021 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact This online talk was presented as a video available to watch at any time during the Camrbidge Festival, and was accompanied by a live online Q&A, which was extremely lively and attracted international attendees due to the online format. The talk explained the use of III-V quantum dots in single photon sources for quantum cryptography.
Year(s) Of Engagement Activity 2021
 
Description Secrets and Lights, Online Lecture, Chester Scibar, 2021 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact A talk was delivered live online to a Chester Scibar. Scibars are regular meeting for adults with an interest in science, which in pre-pandemic times meet in pubs.
Year(s) Of Engagement Activity 2021
 
Description Talk to visiting school group (Communications using light) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact An interactive talk on "Communication using Light" was delivered to a group of sixth formers visiting the department, incorporating elements on LiFi using LEDs and quantum communication using single photon sources.
Year(s) Of Engagement Activity 2016
 
Description The Atomic Gramophone (Science Festival 2018) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact A lecture on microscopy of nanoscale structures at the Cambridge Science Festival
Year(s) Of Engagement Activity 2018
URL https://www.sciencefestival.cam.ac.uk/events/atomic-gramophone