Interband optical absorption in quantum well solarcells

The eigenfunctions and the interband photon absorption of a solar quantum well solar cell are calculated using the K.p Empirical Hamiltonian developed for quantum dot solar cells. The calculations are compared with the measured quantum efficiency in a prototype quantum well solar cell. The agreement is reasonably good. The absorption with quantum wells is found to be much greater than with quantum dots. This is due, besides the higher number of states, to the partially extended nature of quantum well wavefunctions that leads to photon matrix elements which are substantially different to those applicable to quantumdots.

► Application of the empirical k p four band Hamiltonian to the case of quantum wells.
► Definition of the optical absorption matrix elements.
► Detailed calculation of the sub-bandgap photon absorption.
► Reasonable agreement between calculated and measured internal quantum efficiency.