ADVANCED MODELING OF HOT CARRIER EFFECTS IN 3RD GENERATION SOLAR CELLS

摘要

Theoretical works and simulations have shown a very high upper limit for efficiency of an ideal HotCarrier Solar Cell. This limit reaches 86 % under maximal concentration. Such cells require a slowed carriers coolingwhich means a reduced electron-phonon interaction or/and long LO phonon lifetimes. This effect has been observede.g. in GaAs quantum wells structures. Electron-phonon interaction reduction comes from a bottleneck effect on netphonon emission for high carrier density, and then shall only occur with thin layer for absorber and highlyconcentrated sunlight. Ultimately, this phonon bottleneck arises from the finite lifetime of the emitted LO phonons. Ina HCSC one also needs to prevent heat flow when contacting the hot carrier reservoir with a cold one in metallicelectrodes. This is done by using energy selective contacts allowing carriers only at a specific energy to be extracted.In this work, we have developed simulations to (i) obtain LO phonon lifetimes (notoriously difficult to measure) and(ii) evaluate the heating of carrier populations in a realistic absorber.