Infrared Thermophotovoltaic (TPV) cell for power generation and energy harvesting
The studentship aims to demonstrate temperature-stable thermophotovoltaic (TPV) devices with blackbody response ~1000K.
Limited energy resources and pressures of global warming require industry to reduce its net-energy or “carbon footprint”. Given that >60% of energy in manufacturing is wasted as heat has triggered interest in thermal-energy scavenging for temperatures <1000K and worldwide development of thermophotovoltaic (TPV) devices. As early as 2008, Technology Strategy Board (TSB) and EPSRC invested ~£3M creating TPV R&D consortium (Lancaster) with UK first demonstration of InAs TPVs reported in 2015 (co-author, Kesaria). However, the InAs and subsequent InSb-based devices suffer from severe temperature instabilities and require subsequent cooling rendering these devices net-energy-consuming.
Recently, a new compound semiconductor, InN, has been theoretically predicted (2017, MIT) with both thermally-stable crystal structure and spectral response promising robust, un-cooled performance. To date, no diode demonstration has been reported creating a scenario for rich academic exploration/development for PhD study. In support of this studentship, Dr. Kesaria and co-supervisor Prof. Min Gao, are well-placed to explore this opportunity utilising III-N molecular beam epitaxy (MBE), Institute of Compound Semiconductors fabrication and Cardiff device and materials characterization facilities.
Project aims and methods
You will develop new methods to grow InN material using MBE then characterise its structure, optical properties by XRD, PL and FTIR in Ser-Cymru laboratory. Following device simulation (Sentaurus, Gao) and doping studies, a p-i-n structure is grown, fabricated into mesa diodes and characterised. Special flash-test I-Vs will check short-circuit and open-voltage enhancement in Prof Gao’s lab.
Breakthrough opportunities include doping studies (InN is intrinsically n-type), diode passivation (surface accumulation at etched-sidewalls) and InN thermally-stable TPV demonstration (first to date).
This studentship provides tangible skills training in compound semiconductor InN growth using state-of-art MBE reactor. You will develop specialised skills on reflection high-energy electron diffraction and high-resolution X-ray diffraction equipping Ser-Cymru lab to understand crystal structure and material quality. Optical methods will elucidate bandstructure, material quality and doping. Diode fabrication training on conventional dry and wet-etch process is supported by experienced engineers from the Institute of Compound Semiconductors. Training for device testing by I-V, C-V measurement will be conducted within Ser-Cymru laboratory.
TPV prototypes will be tested in thermoelectric laboratory of Prof Gao equipped with solar simulator and thermal/electron transport facilities. Prof. Tony Krier, Lancaster University, leads TPV research in UK, is happy to support this studentship. He will consult and advise on InN TPV diode development to include comparison with benchmarked last-generation InAs and InAsSb TPVs. This collaboration provides student involvement in the UK TPV research community. Given the potential for scientific discovery and strong industrial interest, the student will be trained by Research Innovation Services, the supervisor and co-supervisors in IP development, industrial collaboration and technology transfer.