$\text{CdSe}_{\mathrm{x}}\text{Te}_{1-\mathrm{x}}/\text{CdTe}$ Devices with Reduced Interface Recombination Through Novel Back Contacts and Group-V Doping

Abstract

Since excellent carrier lifetimes and front interface electronic quality are now achieved, rear interface recombination can limit VOC in $\text{CdSe}_{\mathrm{x}}\text{Te}_{1-\mathrm{x}}/\text{CdTe}$ solar cells. Several back-contact structures for devices were fabricated using combinations of tellurium, aluminum oxide, amorphous silicon, and indium tin oxide (ITO). Time-resolved photoluminescence was used to characterize such structures. We show increasingly improved interface passivation through the subsequent use of aluminum oxide, amorphous silicon, and ITO. Additionally, we show that arsenic-doped absorbers form a more passive interface with numerous back contact structures.