Gold Polyiodide Hybrid Perovskite Solar Cells

In this work, we present the ionic liquid (IL) synthesis of two novel pseudo-2D perovskite-type gold­(III)­polyiodide compounds, [DodMe2S]­[AuI4]­[I3] (1) and [Et3S]­[AuI4]­[I5] (2), and their application as active layers in monolithic solar cells. The compounds are composed of tetraiodoaurate anions and polyiodide entities, infinite polyiodide chains in 1 and pentaiodides in 2, which display short intermolecular contacts resulting in relatively small electronic bandgaps. This work represents the first demonstration of film deposition of gold iodide/polyiodide compounds onto porous monolithic substrates with subsequent solar cell characterization. The devices show promising photovoltaic performance and could unlock new materials design possibilities, ultimately moving away from lead-based photovoltaic materials. These findings further highlight the use of simple polyiodide entities to increase the structural and electronic dimensionality of gold perovskite-type anions.