Enhanced photovoltaic properties induced by ferroelectric domain structures in organometallic halide perovskites

Abstract

Organometallic halide perovskites have drawn substantial interest due to their outstanding performance in solar energy conversion and optoelectronic applications. The presence of ferroelectric domain walls in these materials has shown to have a profound effect on their electronic structure. Here, we use a density-functional-based tight-binding model, coupled to nonequilibrium Green’s function method, to investigate the effects of ferroelectric domain walls on electronic transport properties and charge carrier recombination in methylammonium lead–iodide perovskite, MAPbI3. With the presence of ferroelectric domain walls, segregation of transport channels for electrons and holes is observed, and the conductance of perovskites is substantially increased due to the reduced band gap. In addition, by taking into account interactions with photons in the vacuum environment, it is found that electron–hole recombination in perovskites with ferroelectric domain walls is drastically suppressed due to the segregation of carrier transport paths, which could enhance photovoltaic performance.