Science Bridge Award USA: Harnessing Materials for Energy
Lead Research Organisation:
University of Cambridge
Department Name: Materials Science & Metallurgy
Abstract
This Science Bridge proposal builds upon the existing collaboration between the University of Cambridge and the University of California at Santa Barbara to perform the research required to bring existing research through to prototype products and devices in the field of energy-related materials. The proposal has five key themes: organic and inorganic solar cells; light emitting diodes (LEDs) based on gallium nitride (GaN); phosphors for solid-state lighting; organic LEDs (OLEDs); the low-cost integration of LEDs and OLEDs onto printed circuit boards; and ultralight materials and structures.An hour of solar radiation on the Earth provides 14 Terawatt-years of energy, almost the same as the world's total annual energy consumption. However, currently solar energy contributes only 0.03% of the world's energy needs, the main barriers to the widespread use of solar energy being cost and efficiency. The cost of solar cells (typically based on Si or CdTe) is currently too high by a factor of ten relative to other energy sources. The efficiency of solar cells is only 10-15% for Si and 20% for CdTe. We propose two approaches to make solar energy more viable. First, we propose to develop moderate-efficiency (about 15%) organic solar cells at extremely low-cost. UCSB will concentrate on developing more efficient cells and Cambridge will address low-cost manufacturing methods. This requires significant advances in printing methods for organic film deposition.The other approach to solar cells we will pursue is high-efficiency inorganic multilayer solar cells. The basic idea is that by stacking layers in the order of their bandgap, with the layer with the largest bandgap at the top, light is converted into electricity in the most efficient way. We propose to build an innovative multi-layer solar cell based on GaN/InGaN/Si. The GaN layer will absorb the UV part of the solar spectrum, the InGaN layer the blue and green parts and the Si layer the yellow, red and near-IR parts. The theoretical efficiency is above 60%. Such a cell would be too expensive for large-area applications, but would be designed to be used at the focus of mirrors that concentrate the solar light, which will make the technology competitive.GaN-based white lighting is extremely efficient and if used in our homes and offices it could save 15% of the electricity generated at power stations, 15% of the fuel used, and reduce carbon emissions by 15%. However for GaN-based white lighting to become widely used in homes and offices we have to increase the efficiency still further and reduce the cost. We will research various ways to increase the efficiency. To reduce the cost we will grow GaN-based LED structures on 150mm (six-inch) silicon wafers instead of the current growth on two-inch sapphire wafers. This would reduce the LED cost by a factor of ten. Cambridge will grow such LED structures and UCSB will process them into LED lamps.Current white LEDs mainly use a blue LED coated with a yellow phosphor, which gives a cold white light. We will research novel phosphors which give excellent colour rendering, so that skin tones, the colour of clothes, etc, look the same indoors and out. There is increasing evidence that such natural lighting is better for our health than poor quality artificial lighting. We will research OLEDs for large area applications in both displays and lighting. We will also develop the low-cost integration of both LEDs and OLEDs onto printed circuit boards, which will facilitate and reduce the cost of using LEDs and OLEDs.Finally, we will develop novel ultralight materials and structures for use in cars, buses, lorries, trains and planes. These are cellular materials like a honeycomb or 3D lattice. We will develop these using both polymers, metals and composites. Such ultralight materials/structures should save considerable amounts of energy when used in transportation systems such as cars, buses, trains and planes.
Publications
Ashraf H
(2010)
Reduction of the dislocation density in HVPE-grown GaN epi-layers by an in situ SiNx treatment
in Journal of Crystal Growth
Badcock T
(2013)
Evidence for Dark States in the Temperature Dependent Recombination Dynamics of InGaN/GaN Quantum Wells
in Japanese Journal of Applied Physics
Badcock T
(2012)
Recombination mechanisms in heteroepitaxial non-polar InGaN/GaN quantum wells
in Journal of Applied Physics
Badcock T
(2010)
Characterising the degree of polarisation anisotropy in an a -plane GaN film
in physica status solidi c
Badcock T
(2011)
Modification of carrier localization in basal-plane stacking faults: The effect of Si-doping in a -plane GaN
in physica status solidi (b)
Badcock T
(2009)
Optical polarization anisotropy of a-plane GaN/AlGaN multiple quantum well structures grown on r-plane sapphire substrates
in Journal of Applied Physics
Badcock T
(2011)
Properties of surface-pit related emission in a -plane InGaN/GaN quantum wells grown on r -plane sapphire
in physica status solidi c
Badcock T
(2013)
Carrier Density Dependent Localization and Consequences for Efficiency Droop in InGaN/GaN Quantum Well Structures
in Japanese Journal of Applied Physics
Badcock T
(2010)
Carrier dynamics in non-polar GaN/AlGaN quantum wells intersected by basal-plane stacking faults
in physica status solidi c
Badcock T
(2009)
Optical polarisation anisotropy in a -plane GaN/AlGaN multiple quantum well structures
in physica status solidi c
Description | Three spin-out companies have been formed through the research performed on this grant. One of these, PervasID, arose from the research performed by the group of Professor White. Two of his post-docs supported on this grant, Dr Crisp and Dr Sithamparanathan, formed a new spin-out company in 2011, PervasID, largely based on the research they performed on this grant. The research developed RFID tags to provide location information through accurate wireless tracking and sensing. The company is applying this in several sectors, including retail, security and logistics. It can also detect files in medical or legal offices, for example. Existing RFID tags used on clothing and other items have a detection range of only a few metres, and so a shop assistant has to check each tag with a handheld reader. The PervasID system uses a network of antennas. providing extensive coverage over a large area, such as a large building. It is new technology that satisfies an unmet need. Apart from the new company, the work on this grant has let to White's group being awarded two follow-on grants from the EPSRC and one from Boeing. A further major success has been the work performed by Professors Deshpande and Fleck, in collaboration with UCSB in the USA. They have been working on the development of new ultra-lightweight materials and structures. These are cellular materials like a honeycomb or 3D lattice. Such ultralight materials/structures should save considerable amounts of energy when used in transportation systems such as cars, buses, trains and planes. Their work on new lightweight energy absorbing materials has been taken up by HRL Laboratories in Malibu, California. It has also formed the basis of two new projects in Cambridge funded by DARPA. In collaboration with UCSB, they have developed a model for optimising the use of ceramic materials in vehicle applications. In addition to the grants from DARPA mentioned above, their work has resulted in two further follow-up grants to Cambridge from the USA Office of Naval Research. The vision of the Humphreys' research group was to grow GaN LEDs on large-diameter (6-inch) Si wafers. This Science Bridge Award enabled us to develop this research, apply for a patent, set up a company, CamGaN, in 2010 and another company, Intellec, in 2011. Both companies were acquired by the UK company Plessey in 2012, which also hired 3 of Humphreys' post-docs who transferred the technology. We were told that it would take two years to transfer the technology from our university to Plessey. In fact it took only eight weeks. Plessey has been manufacturing since 2013 millions of GaN LEDs on Silicon at its factory in Plymouth based on our technology. Plessey has stated that our technology will reduce the cost of GaN LEDs by factor of 5, so that a 60W replacement light bulb should cost less than £5. in fact it now (March 2019) costs only £3. Further economies of scale should enable the widespread adoption of LED lighting in our homes and offices, which is already happening (March 2019). When LED lighting is even more widespread in the UK, which will happen in the next few years, this will save the UK £2 billion pa electricity costs and 10% CO2 emissions from power stations. Our research has also created the first ever manufacturing of GaN LEDs in the UK, at Plessey in Plymouth. Plessey are now (2019) making the best microLEDs in the world, with a diameter as small as 1 micron, for use as displays in smart watches, mobile phones and cameras, where the image is visible in bright sunlight. In summary, this grant has resulted in a number of very successful outcomes. |
Exploitation Route | Our findings are already being used by various industries, please see statements above |
Sectors | Aerospace Defence and Marine Construction Digital/Communication/Information Technologies (including Software) Electronics Energy Environment Healthcare Manufacturing including Industrial Biotechology Transport |
URL | http://www.gan.msm.cam.ac.uk |
Description | Many shop sales are lost because the shopper can't find the size he or she wants, even though the item might be available in the stockroom. A major success of this grant was the research performed by the group of Professor White to solve this problem. Two of his post-docs supported on this grant, Dr Crisp and Dr Sithamparanathan, formed a new spin-off company in 2011, PervasID, largely based on the research they performed on this grant. The company won its first order in 2013 and secured investment of £720,000 in 2016 to take the business to the next level. PervasID has launched the world's first cost-effective and nearly 100 percent accurate, wide area RFID system for retail shops, which will automate real-time inventory management and stock control and remove the need for handheld readers. Passive RFID tags currently used on clothes and other items are cheap and don't need batteries, but have a reliable detection range of only 2-3 metres and so require the shop assistant to check each tag with a handheld reader. The next generation PervasID system uses a network of antennas located discreetly at intervals across the shop floor and stockroom. A single RFID reader can cover up to 400 m2 with almost 100 percent detection accuracy, capable of easily scaling to a large building, allowing automatic monitoring of nearly all the tags and constant update of stock control. Low cost, long distance sensing of passive RFID tags is an unmet need in the retail and logistics industries. PervasID is a technology game changer that facilitates a move towards the 'Internet of Things'. Apart from the new company, the work on this grant has let to White's group being awarded two follow-on grants from the EPSRC and one from Boeing. A further major success has been the work performed by Professors Deshpande and Fleck, in collaboration with UCSB in the USA. They have been working on the development of new ultra-lightweight materials and structures. These are cellular materials like a honeycomb or 3D lattice. Such ultralight materials/structures should save considerable amounts of energy when used in transportation systems such as cars, buses, trains and planes. Their work on new lightweight energy absorbing materials has been taken up by HRL Laboratories in Malibu, California. It has also formed the basis of two new projects in Cambridge funded by DARPA. In collaboration with UCSB, they have developed a model for optimising the use of ceramic materials in vehicle applications. In addition to the grants from DARPA mentioned above, their work has resulted in two further follow-up grants to Cambridge from the USA Office of Naval Research. A further success story has been our development of low-cost LED (light emitting diode) lighting. This research on this grant was performed in parallel with my grants "Nitrides for the 21st Century" and "Lighting the Future". The three grants together gave me the manpower required. This Science Bridge Award funded the more developmental aspects of the research and paid for our key Patent, which enabled us to move fast on the patenting and was extremely helpful. LED lighting will save the UK £billions per year in electricity costs and has been commercialised in the UK by Plessey, thanks to our EPSRC support. Electricity generation is the main source of energy-related greenhouse gas emissions. Lighting uses one-fifth of its output. LEDs are poised to reduce this figure by 50%. Lighting will then use 10% of all electricity, which will save 10% of the electricity generated in power stations and save 10% of the CO2 emissions from power stations. If the UK changed to LED lighting in our homes and offices we could close (or not build) 10 large power stations (or hundreds of wind turbines) and save £2 billion pa electricity costs. The reason this did not happen earlier was cost. Whereas low-power LEDs are cheap, costing only a few pence, high-power LEDs for lighting were expensive. For example, a Philips 60W replacement bulb (using 12W LEDs) cost £25 in 2013, and not many people would pay this cost. All commercial GaN LEDs were grown on small-diameter sapphire or SiC wafers, which is why they were expensive. The vision of the Humphreys' research group was to grow GaN LEDs on large-diameter (6-inch) Si wafers. This Science Bridge Award enabled us to develop this research, apply for a patent, set up a company, CamGaN, in 2010 and another company, Intellec, in 2011. Both companies were acquired by the UK company Plessey in 2012, which also hired 3 of Humphreys' post-docs who transferred the technology. Plessey is manufacturing at its factory in Plymouth (an unemployment blackspot) millions of LEDs per year based on our technology. Production started in the summer of 2013. Our technology reduces the cost of GaN LEDs by factor of 5, so that a LED 60W replacement light bulb should cost less than £4 (note added in 2019: it now costs only £3). Economies of scale will reduce the price further and enable the widespread adoption of LED lighting in our homes and offices, which is now happening. GaN LEDs will save the UK £2 billion pa electricity costs and 10% CO2 emissions from power stations. Our research has also created the first ever manufacturing of blue and white LEDs in the UK. In summary, this grant has resulted in a number of very successful outcomes. |
First Year Of Impact | 2012 |
Sector | Construction,Digital/Communication/Information Technologies (including Software),Electronics,Energy,Environment,Healthcare,Manufacturing, including Industrial Biotechology,Retail,Transport |
Impact Types | Societal Economic |
Description | EPSRC |
Amount | £560,766 (GBP) |
Funding ID | EP/J003603/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 03/2009 |
End | 10/2012 |
Description | EPSRC |
Amount | £6,361,650 (GBP) |
Funding ID | EP/I012591/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 12/2010 |
End | 11/2015 |
Description | EPSRC |
Amount | £826,500 (GBP) |
Funding ID | EP/H019324/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 11/2009 |
End | 10/2014 |
Description | Platform Grant |
Amount | £826,500 (GBP) |
Funding ID | EP/H019324/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 11/2009 |
End | 10/2014 |
Description | Programme Grant: Lighting the Future |
Amount | £6,361,650 (GBP) |
Funding ID | EP/I012591/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 12/2010 |
End | 11/2015 |
Description | Study of semi-polar and non-polar nitride based structures |
Amount | £560,766 (GBP) |
Funding ID | EP/J003603/1 |
Organisation | Engineering and Physical Sciences Research Council (EPSRC) |
Sector | Public |
Country | United Kingdom |
Start | 01/2012 |
End | 12/2014 |
Description | Aixtron |
Organisation | Aixtron Limited |
Country | United Kingdom |
Sector | Private |
PI Contribution | We grew world class GaN device structures on our Aixtron reactor(s), thus increasing Aixtron sales. |
Collaborator Contribution | They donated to us a senior scientist for 25% of his time. They provided free servicing and maintenance of our growth reactor. |
Impact | Increased sales of Aixtron growth reactors. |
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 |
Title | SEMICONDUCTOR MATERIAL |
Description | The present invention relates to a semiconductor wafer comprising: a substrate; a first Al Ga N layer on the substrate; a second Al Ga N layer on the first Al Ga N layer; a Ga N layer on the second Al Ga N layer; and a plurality of crystalline Ga N islands between the first and second Al Ga N layers. |
IP Reference | WO2014053831 |
Protection | Patent application published |
Year Protection Granted | 2014 |
Licensed | Commercial In Confidence |
Impact | This development will reinforce the GaN-on-Si technology developed in Cambridge centre for GaN, which provides an alternative way to achieve high performance GaN-on-Si LEDs. Commercial exploitation of this discovery is under discussion. |
Title | SEMICONDUCTOR WAFER COMPRISING GALLIUM NITRIDE LAYER HAVING ONE OR MORE SILICON NITRIDE INTERLAYER THEREIN |
Description | The present invention provides a semiconductor wafer comprising: a substrate layer; and a first GaN layer having one or more SiNx interlayers therein; and wherein in the first GaN layer at least one SiNx interlayer has GaN penetrated through one or more portions of said SiNx interlayer and preferably has a thickness of from 0.5 to 10nm. |
IP Reference | WO2012066269 |
Protection | Patent granted |
Year Protection Granted | 2012 |
Licensed | Yes |
Impact | This patent was transferred to a Cambridge spin-out, CamGaN Ltd, for commercial exploitation of the technology described in the patent. CamGaN was later acquired by Plessey semiconductors in 2012. A portfolio of products based on the CamGaN technology has been launched by Plessey and has generated positive market feedback. |
Company Name | CamGaN |
Description | CamGaN develops new high-brightness LED technologies. |
Year Established | 2010 |
Impact | CamGaN was formed in 2010 to commercialise a novel technology (GaN LEDs on large-area (150 mm diameter) silicon) for the cost-effective manufacture of key components of high-brightness LEDs. This novel technology holds strong potential to dramatically reduce the cost of solid-state lighting devices that are rapidly replacing incandescent and fluorescent light bulbs. Plessey acquired CamGaN in 2012. In 2014 they manufactured over 2 million LEDS based on this technology. Recently they have raised £60m to expand production capacity and this will employ 400 more people in Plymouth. The widespread use of LED lighting in the UK will save 10% of all our electricity used and 10% of carbon emissions from power stations. We are continuing to develop this work on current EPSRC grants. See also my entry under my spin-out company Intellec. |
Website | http://www.camgan.com |
Company Name | PervasID |
Description | PervasID develops a wide-range radio-frequency tracking system. |
Year Established | 2011 |
Impact | The company recently raised over £800,000 in investments to take its products to the next level, for use in retail, security and logistics. |
Website | http://www.pervasid.com |
Company Name | Intellec Ltd. |
Description | |
Year Established | 2011 |
Impact | Intellec and CamGaN were taken over by Plessey in 2012. Plessey are now manufacturing millions of LEDs each year based on our technology. They are manufacturing in the UK, in Plymouth. Over 100 people are employed by Plessey in the UK on manufacturing our LEDs. Plessey raised £30 million from Deutsche Bank and £30 million from other investors in September 2015 to expand their manufacturing capabilities. Humphreys is a member of the Plessey Advisory Board. We continue to work with them on a variety of EPSRC grants. See also the entry under my spin-out company CamGaN. |
Website | http://www.plesseysemi.com |
Description | BBC Breakfast TV and BBC Radio "You and Yours" |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Public/other audiences |
Results and Impact | Interview of Prof Humphreys on BBC Breakfast TV, and on the BBC Radio "You and Yours" on low-cost LEDS sparked a lot of discussions Increased public awareness of LEDs |
Year(s) Of Engagement Activity | 2009 |
Description | Big Bang Fair (London) |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | Yes |
Geographic Reach | National |
Primary Audience | Schools |
Results and Impact | Encouraged school pupils to study science Schools reported increased interest in science and increased numbers studying science |
Year(s) Of Engagement Activity | 2013,2014 |
Description | Chelterham Science Festival |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | Yes |
Geographic Reach | National |
Primary Audience | Schools |
Results and Impact | More school pupils studying science Schools reported greater interest in science. |
Year(s) Of Engagement Activity | 2013,2014 |