Fundamental studies of zincblende nitride structures for optoelectronic applications
Lead Research Organisation:
University of Cambridge
Department Name: Materials Science & Metallurgy
Abstract
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Organisations
Publications
Alanis J
(2018)
Optical Study of p-Doping in GaAs Nanowires for Low-Threshold and High-Yield Lasing
in Nano Letters
Barrett R
(2021)
Effect of Micron-scale Photoluminescence Variation on Droop Measurements in InGaN/GaN Quantum Wells
in Journal of Physics: Conference Series
Binks D
(2022)
Cubic GaN and InGaN/GaN quantum wells
in Applied Physics Reviews
Church S
(2018)
Effect of stacking faults on the photoluminescence spectrum of zincblende GaN
in Journal of Applied Physics
Church S
(2020)
Stacking fault-associated polarized surface-emitted photoluminescence from zincblende InGaN/GaN quantum wells
in Applied Physics Letters
Church S
(2021)
Photoluminescence efficiency of zincblende InGaN/GaN quantum wells
in Journal of Applied Physics
Ding B
(2021)
Combined SEM-CL and STEM investigation of green InGaN quantum wells
in Journal of Physics D: Applied Physics
Ding B
(2021)
Multimicroscopy of cross-section zincblende GaN LED heterostructure
in Journal of Applied Physics
Ding B
(2020)
Alloy segregation at stacking faults in zincblende GaN heterostructures
in Journal of Applied Physics
Dyer D
(2021)
The effect of thermal annealing on the optical properties of Mg-doped zincblende GaN epilayers
in Journal of Applied Physics
| Description | It has been discovered that the emission from cubic quantum wells (QWs) is strongly polarized at room temperature. This means that LEDs based on such QWs can be used in devices such as displays making them significantly more efficient. Currently, the need for a separate polariser in LCD displays means that upto 50% of the light is thrown away. |
| Exploitation Route | A patent has been filed based on the discovery of polarised emission from cubic-GaN LEDs and a licenece has been signed with a company called Kubos Semiconductors Ltd to develop this technology in to commercial devices |
| Sectors | Digital/Communication/Information Technologies (including Software),Electronics |
| Description | The findings have formed the basis of a patent application and a licencing agreement ahs been signed with a company to further develop this technology |
| First Year Of Impact | 2019 |
| Sector | Digital/Communication/Information Technologies (including Software),Electronics |
| Impact Types | Economic |
| Description | Fast Switching Zincblende GaN LEDs |
| Amount | £473,432 (GBP) |
| Funding ID | EP/W034956/1 |
| Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 12/2022 |
| End | 11/2025 |
| 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 "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 "Investigation of wurtzite formation in MOVPE-grown zincblende GaN epilayers on AlxGa1-xN nucleation layers" |
| Description | The data consists of Scanning transmission electron microscopy based Energy-dispersive X-ray spectroscopy measurements. Data consists of the information from the Line profile obtained across the AlGaN (x=0.29) nucleation layer for different elements such as Si Ka, Pt Ma, Ga La, Al Ka. The second file (dm3 file) is a cross-sectional HRTEM image (zone axis = [110]) of the zb-GaN epilayer on GaN NL grown over 3C-SiC, shown in figure 1 of the associated publication (https://doi.org/10.1063/5.0077186). |
| Type Of Material | Database/Collection of data |
| Year Produced | 2022 |
| Provided To Others? | Yes |
| URL | https://www.repository.cam.ac.uk/handle/1810/337300 |
| 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 | Quantum Wires in Cubic group III Nitrides |
| Description | GaN-related structures in the cubic/zincblende phase are known as a promising alternative to the more widely-known wurtzite/hexagonal GaN semiconductors, and may be used to achieve improved efficiencies for long-wavelength (including Green amber and red) LEDs. Semiconductors, such as those comprising GaN, are known to give rise to photo-luminescent and electro-luminescent properties, where such semiconductors may be used in LED or photo-diode devices. Group-Ill nitride semiconductors generally offer a wide range of optoelectronic applications including LEDs, and laser diodes emitting in the blue, green, and red spectral region. However, conventional LED sources still require separate polarisation filters when used in display technology, which inherently reduces the transmission of light, and thus reduces efficiency of the system. Thus, it would be advantageous to obtain a polarised light source for use in LD or LCD displays, or other such devices requiring a polarised light source. |
| IP Reference | PC928981GB |
| Protection | Patent / Patent application |
| Year Protection Granted | 2019 |
| Licensed | Yes |
| Impact | This patent application has been licenced to a spin-out company called Kubos Semiconductors Ltd. kubos is currently futher developing this technology and IP to allow commercial exploitation. |
| 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 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 | 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 |