Theoretical study of the effects of n-type doping in InAs/GaAs quantum dot layer on current–voltage characteristics of intermediate band solar cells

Abstract

We theoretically investigated the current–voltage characteristics of InAs/GaAs quantum dot intermediate band solar cells (QD IBSCs) with different n-type doping concentrations in the QD layer. When the optical absorption coefficients are low, the QD layer negatively affects conversion efficiency because it acts as a recombination center. As the n-type doping concentration increases, the negative effect of the QD layer is gradually suppressed. When the optical absorption coefficients are high, the QD layer can induce additional energy conversion. As the n-type doping concentration increases, the positive effect of the QD layer is also gradually suppressed. The electron occupation factor in the intermediate band varies not only with the doping concentration but also with the output voltage, and in our simulation model n-type doping cannot improve the efficiency of the QD IBSCs.