Impact of semiconductor quantum dots bandgap on reabsorption in luminescent concentrator

Abstract

We have investigated the influence of the average radius and its dispersion of the semiconductor quantum dots (QDs) used in luminescent solar concentrators (LSCs) on reabsorption. To minimize the detrimental reabsorption losses in LSCs, six semiconductors used to fabricate QDs with a wide range of their bulk band gap Eg0 have been considered, specifically: CdS (Eg0 = 2.42 eV), CdSe, (Eg0 = 1.67 eV), CdTe (Eg0 = 1.5 eV), InP (Eg0 = 1.27 eV), InAs (Eg0 = 0.355 eV), and PbSe (Eg0 = 0.27 eV). Altering and , we can determine the optimal size for minimal reabsorption. As it was shown, decreasing the semiconductor bulk band gap from 2.42 down to 1.24 eV we can get such optimum QD size that reabsorption reduces even below the combined experimental error in determination of the absorption coefficient and luminescence intensity. Further reduction of the gap Eg0, however, increases reabsorption at any values of r and Δr: for instance, for PbSe-based QDs of 1-nm radius and dispersion of 1%, reabsorption reaches 54%.

Keywords

• photoluminescence
• quantum dots
• luminophor
• reabsorption
• solar panels
• efficiency
• concentrator