Effect of embedded chalcogenide quantum dots in PbBr2 film on CsPbBr3 inorganic perovskite solar cells

Abstract

Inorganic perovskite solar cells (PSCs) are considered prospective alternatives to organic PSCs due to their efficiency and relative stability. Cesium lead bromide (CsPbBr3) has a complete perovskite structure, is phase stable, exhibits a wide bandgap energy of 2.3eV under operating conditions, and is regarded as a suitable material not only for stable PSCs, but also for semi-transparent PSCs. In this study, we synthesize Cu–Zn–In–S–Se (CZISSe) quantum dots (QDs) and demonstrate their novel use for improving the performance of PSC devices. QDs are embedded through ligand-exchange, which replaces long organic chains with thiosulfate (–S2O3) ligands and disperses the S2O3-capped QDs in the PbBr2 solution to prepare QD-blended precursor inks. The QDs promote the crystallization of CsPbBr3 and hole extraction from the photoactive layer. As a result, the optimized power conversion efficiency (PCE) of the QD-incorporated PSC is 5.37%, which is a 22.6% enhancement compared to those of the control devices. This work provides an effective and simple process for enhancing the performance of CsPbBr3-based PSCs.