A report on the demonstration of proof-of-concept Hot Carrier cells towards the development of a high efficiency, low cost device.
Report extract
The goal of this project was to demonstrate proof-of-concept Hot Carrier solar cells toward the development of a high efficiency, low cost device. The HC solar cell is a promising advanced photovoltaics or so called “third generation” concept which aims to tackle the major loss in conventional solar cells that most of the energy of high energy blue photons in the solar spectrum is lost as heat before the electrons excited by the photons can be extracted as an electrical current.
These photo-excited “hot” carriers (carriers with energy above the fundamental energy level of the solar cell – the ‘band gap energy’) lose their excess energy as heat or lattice vibrations in a few trillionths of a second. The limiting efficiency of the HC solar cell is 65% for non-concentrated solar radiation, whereas it is more than 85% for maximally concentrated sunlight.