Comparative study of InAs/GaAs quantum dots and GaSb/GaAs quantum rings for recombination suppression in thin-film intermediate band solar cells

We investigate the performance of thin-film solar cells incorporating InAs/GaAs quantum dots (QDs) and GaSb/GaAs quantum rings (QRs). The goal is to compare their impact on key parameters such as short-circuit current density and open-circuit voltage, with a focus on recombination suppression and light absorption properties. InAs/GaAs QDs with a type-I band structure show a higher light absorption, whereas GaSb/GaAs QRs with a type-II band structure exhibit a suppressed carrier recombination. Experimental results indicate that QR-based solar cells can reach higher efficiencies due to reduced carrier recombination, despite their lower absorption compared with QD-based solar cells. The findings suggest that GaSb/GaAs QRs offer a promising potential for enhancing solar cell performance through improved carrier lifetimes and reduced recombination losses.