Multiple exciton generation in PbSe and PbS nanocrystals incorporated into amorphous silicon p–n junction

Abstract

AbstractThe effect of multiple exciton generation in semiconductor nanocrystals suggesting the possibility of efficient conversion of each absorbed high‐energy photon into at least two electron–hole pairs (excitons) is demonstrated in the photocurrent from lead selenide (PbSe) and lead sulfide (PbS) colloidal nanocrystals incorporated into amorphous silicon p–n junction. It is shown that employment of this effect for increasing efficiency of solar cells requires such energy bandgap alignment in the system that ensures confinement of the photogenerated charge carriers inside the nanocrystal layer.