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.