Solar cells typically operate at temperatures below 100 °C. A new class of 'refractory' solar cells was presented at the 43rd IEEE Photovoltaic Specialist Conference in June 2016. These new cells are stable at tempertures over 600 °C.
In addition to applications in CSP-CPV hybrid plants, these cells open up new application areas for solar cells. Those applications include power beaming for wireless recharging of electric UAV’s, high temperature cells for space probes to Venus and Mercury, and deployment in nuclear-photovoltaic hybrids.
The cells were produced by a team of scientists from QESST at ASU and corporate partner Photonitride Devices, Inc. have produced a solar cell capable of sustained operation at temperatures of 600°C, a record in the field. These devices, leveraged on blue-LED technology, are made possible with InGaN quantum wells in a GaN diode. Due to the nature of these cells ability to produce power while at such extreme temperatures, we have identified them as new class of solar cells, “refractory solar cells.” These results and corresponding analysis were presented as a talk at the 43rd IEEE Photovoltaic Specialist Conference in June 2016, and submitted for publication in the Journal of Photovoltaics.
This technology expands the range of environments into which photovoltaic technology can be deployed. The motivation application for this work was as a thermal topping cell on the receiver of a CSP (concentrated solar power) power plant. This allows direct conversion of electricity from sun-light, a more efficient process than the use of light to heat to mechanical energy to electricity. Additionally, as a thermal topping cell all inefficiencies become heat which transfers to the thermal receiver regardless.
Explanation and Background:
GaN and related InGaN materials have enabled the LED lighting revolution our society is currently experiencing. The industry surrounding these semiconductor technologies has grown exponentially. This technology also has use as an enabling material for solar cells. By modifying the structure of a blue LED, we are able to make InGaN solar cells.
Furthermore, the GaN and InGaN materials are naturally stable at high temperatures (both chemically and electrically). This is due the strength of the group III-N atomic bonds and the wide band gap of the material. The end result being that these materials are capable of creating photovoltaic devices operable at temperatures far hotter than any other PV technology