Electron irradiation induced aging effects on radiative recombination properties of quadruple cation organic-inorganic perovskite layers

Abstract

Understanding the role of defects in hybrid organic inorganic perovskites (HOIPs) is critically important to engineer the stability and performance of photovoltaic devices based on HOIPs. Recent reports on multi-cation compositions of general formula (A 1 ,A 2 ,A 3 ,A 4)Pb(X 1 ,X 2 ,X 3) 3 , where the A sites can be occupied by a distribution of 2-4 metallic/ organic cations and X sites with halide anions have shown stabilization effects against the well-known methyl ammonium lead triiodide (CH 3 NH 3 PbI 3), although the underlying mechanism is not fully elucidated. Herein, polycrystalline layers of 4APb(IBr) 3 perovskite, where A is occupied by a combination of Cs + (cesium ion), GA + (guanidinium), MA + (methylammonium), and FA + (formamidinium) ions were synthesized. To gain insight on the role of intrinsic defects, electron irradiation was used for introducing point defects in a controlled way in the quadruple-cation HOIPs. Our results show that the engineered defects in perovskites strongly influenced the absorption, photoluminescence, and time-resolved photoluminescence of these materials, probably due to introduction of additional energy levels that modify electronic and light emitting properties of the material. Furthermore, the irradiation-induced defects were found to strongly affect the aging behavior of HOIPs and modify their radiative recombination properties.

Doping Strategies for Promising Organic–Inorganic Halide Perovskites

“…[144,164] In study of GA 0.015 Cs 0.046 MA 0.152 FA 0.787 Pb(I 0.815 Br 0.185 ) 3 , the defects can be controlled by electron irradiation, which further influence the photoelectric properties and stability. [165] A-X Sites Doping in LD POIHPs: The 2D-3D mixed perovskite with A and X sites doping is found. [145,166,167] The n-propylammonium iodide (PAI) can be added into FA 0.79 MA 0.16 Cs 0.05 PbI 2.5 Br 0.5 , which forms 2D-3D mixed (PA) 2x FA 0.79 MA 0.16 Cs 0.05 Pb 1+x I 2.5+4x Br 0.5 system, where the Cs + can suppress photoinactive δ-phase of FAPbI 3 while PA promotes the energy level match (Figure 7c), reduces recombination and trap states in perovskite, and forms a 2D (PA) 2 PbI 4 covering layer with RPP crystal structure that changes wettability of the film surface to become hydrophobic against humid environment.…”

“…[ 144,164 ] In study of GA 0.015 Cs 0.046 MA 0.152 FA 0.787 Pb(I 0.815 Br 0.185 ) 3 , the defects can be controlled by electron irradiation, which further influence the photoelectric properties and stability. [ 165 ]…”

Oxygen-deficient perovskites for oxygen evolution reaction in alkaline media: a review

“…Several experimental and theoretical studies demonstrated that the catalytic activity of perovskite oxides can be intrinsically modulated through the inductive alteration of oxygen nonstoichiometry to generate oxygen-deficient structures for a myriad of applications [35][36][37][38][39]. Table 1 summarizes various electrocatalysts made of oxygen-defected perovskite oxides that were reported in the literature for OER.…”