Organic\nDye/Cs₂AgBiBr₆ Double\nPerovskite Heterojunction Solar Cells

Abstract

The photovoltaic performance of Cs₂AgBiBr₆ perovskite is limited by its light-harvesting\nability owing to its\nbroad bandgap. Here, we introduced three indoline dyes, D102, D131,\nand D149, to sensitize the TiO₂ electron transport layer\nthat was employed in the Cs₂AgBiBr₆ perovskite\nsolar cells (PSCs). The perovskite–indoline dye hybrid cells\nworked with higher power conversion efficiencies (PCEs) than the corresponding\ndye-sensitized solar cells and the PSC. Extended absorption resulted\nin a higher short-circuit current density, up to 8.24 mA cm^–2, and a maximum PCE of 4.23% in the case of D149, for instance. The\ndouble perovskite worked as a p-type interlayer between the dyes and\nspiro-OMeTAD to convey the holes from the former to the latter, resulting\nin enhancement in the overall performance.