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, MAPbI 3 . 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.

Twin Domains in Organometallic Halide Perovskite Thin-Films

“…The accumulation of charge carriers increased the static conductivity of the domain wall by 3-4 orders compared to the bulk state [78]. Recently, the density function theory based model revealed a similar segregation transport of electrons and holes with increased conductance and reduced bandgap in MAPbI 3 [79]. [20].…”

On the Current–Voltage Hysteresis in Perovskite Solar Cells: Dependence on Perovskite Composition and Methods to Remove Hysteresis

“…Photoferroelectric property was observed from 2D bis(cyclohexylaminium) tetrabromo lead perovskite, where polarization characteristics was proposed to be related to superior photovoltaic property of PSC . Along with theoretical approaches, experimental evidences on ferroelectricity were also reported, where tetragonal phase of single crystal MAPbI 3 was ferroelectric and self‐organized, room‐temperature stable ferroelectric domain might affect charge carrier extraction . Regarding origin of ferroelectricity, off‐center displacement of lead in lead‐iodide octahedral was suggested to be origin of ferroelectricity, while dipole ordering of organic cation is related to ferroelectricity .…”

Revealing the Chemistry between Band Gap and Binding Energy for Lead‐/Tin‐Based Trihalide Perovskite Solar Cell Semiconductors

“…Similarly,C H 3 NH 3 PbI 3 , [40][41][42][43][44][45][46][47][48][49][50] the formamidinium (FA) lead triiodide perovskite (HC(NH 2 ) 2 PbI 3 )s olar cell, is also ferroelectric, [50] but CsPbI 3 is not ferroelectric, ratherh ysteretic. [51] Equally, CH 3 NH 3 PbBr 3 and HC(NH 2 ) 2 PbBr 3 are possible ferroelectrics, but CsPbBr 3 is not;t he latter is an excellent halide conductor.…”