Theoretical analysis of GaAs/AlGaAs quantum dots in quantum wire array for intermediate band solar cell

Abstract

A GaAs quantum dot (QD) array embedded in a AlGaAs host material was fabricated using a strain-free approach, through combination of neutral beam etching and atomic hydrogen-assisted molecular beam epitaxy regrowth. In this work, we performed theoretical simulations on a GaAs/AlGaAs quantum well, GaAs QD and QD array based intermediated band solar cell (IBSC) using a combined multiband k·p and drift-diffusion transportation method. The electronic structure, IB band dispersion, and optical transitions, including absorption and spontaneous emission among the valence band, intermediate band, and conduction band, were calculated. Based on these results, maximum conversion efficiency of GaAs/AlGaAs QD array based IBSC devices were calculated by a drift-diffusion model adapted to IBSC under the radiative recombination limit. © 2013 AIP Publishing LLC.