Modeling Hot Carriers Quantum Well Solar Cells

Abstract

The effects of carrier escape from quantum well (QW) and the interaction of hot electrons with crystal lattice are of importance to the physical understanding of QW hot carrier solar cells when the cooling dynamics in photo-excited structures affect the cell efficiency. The absorption of high-energy photons produces electron hole pairs with excess kinetic energy, which are dissipated to the lattice thru phonon scattering. These hot electrons alter the conversion efficiency in photovoltaic solar cells. We have studied hot electron effects in an AlxGa1-xAs / GaAs p-i-n structure with quantum wells are placed in the intrinsic region similar to the experimental device structure reported by others. Our results show that hot electrons lead to an increase in short circuit current. The increase in short circuit current is due to carriers escaping from the well without any significant recombination loss which leads to a higher cell efficiency. These results support the experimental data recently published by others.