US research reveals 'hot carrier' secrets

摘要

Researchers at the Lawrence Berkeley National Laboratory in the US have developed the first ab initio method to characterise the properties of "hot carriers" in semiconductors. Hot carriers are electrical charge carriers - electrons and holes - with significantly higher energy than charge carriers at thermal equilibrium. The work could pave the way towards more efficient solar cells and other optoelectronic devices. Steven Louie, a theoretical physicist and senior faculty scientist with Berkeley Lab's Materials Sciences Division, said: "Hot carrier thermalisa-tion is a major source of efficiency loss in solar cells but because of the sub-picosecond time scale and complex physics involved, characterisation of hot carriers has long been a challenge.