Study of excitonic carrier dynamics in quantum dot solar cells by numerical simulations

Abstract

This paper presents a theoretical study about the influence of fully correlated electron and holes on the performance of quantum dot solar cells. A device-level model combining drift-diffusion equations for bulk carriers and rate equations for carrier dynamics in the quantum dot states, developed ad hoc by some of the authors, was applied to investigate the internal processes involved in the operation of InAs/GaAs quantum dot solar cells, considering excitonic capture and escape dynamics. It is demonstrated, in line with previous theoretical and experimental works, that the excitonic behavior of carriers in the nanostructures could be the responsible of the non-additive characteristic of the quantum dot contribution to the total solar cell photocurrent. Separate carrier capture and escape are also investigated and compared to the excitonic dynamics.