A new approach to predict the formation of 3D hybrid organic‐inorganic perovskites

Abstract

AbstractRecently, hybrid organic‐inorganic perovskite (HOIPs) materials are used to enhance the power conversion efficiency of the solar cells. The tolerance factor (TF) and octahedral factor (μ) are widely used to predict the formation of three‐dimensional (3D) HOIPs structures. However, in some of the cases (e.g. CH3NH3GeI3 (MAGeI3) [TF = 1.06, μ = 0.33] NH2CHNH2GeI3 (FAGeI3) [TF = 1.14, μ = 0.33] and CH3C(NH2)2GeI3 (ACGeI3) [TF = 1.17, μ = 0.33]), these factors could not predict the formation of HOIPs structures. Thus, we have introduced a new factor based on the HOMO‐LUMO energy gap of the organic cations, metal cations, anions, and volume of the organic cations. We have tested and utilized the HOMO‐LUMO energy gap factor (β) on 403 ABX3 combinations. The factor β successfully predicts and differentiate the perovskite and non‐perovskite materials. Further, we also observed that for the formation of HOIPs structure, volume of the organic cation should also be in the range of 20 to 46 cm3/mol. Based on the newly reported factor, we have also designed some new organic cations which may form a 3D HOIPs structure.