Formability of ABX ₃ (X = F, Cl, Br, I) halide perovskites

Abstract

In this study a total of 186 complex halide systems were collected; the formabilities of ABX3 (X = F, Cl, Br and I) halide perovskites were investigated using the empirical structure map, which was constructed by Goldschmidt's tolerance factor and the octahedral factor. A model for halide perovskite formability was built up. In this model obtained, for all 186 complex halides systems, only one system (CsF-MnF2) without perovskite structure and six systems (RbF-PbF2, CsF-BeF2, KCl-FeCl2, TlI-MnI2, RbI-SnI2, TlI-PbI2) with perovskite structure were wrongly classified, so its predicting accuracy reaches 96%. It is also indicated that both the tolerance factor and the octahedral factor are a necessary but not sufficient condition for ABX3 halide perovskite formability, and a lowest limit of the octahedral factor exists for halide perovskite formation. This result is consistent with our previous report for ABO3 oxide perovskite, and may be helpful to design novel halide materials with the perovskite structure.

Organic–inorganic metal halide hybrids beyond perovskites

“…The crystallographic stability of this ABX 3 structure could be estimated by the Goldschmidt tolerance factor t = (r A + r B )/ √ 2(r B + r X ) and octahedral factor μ = r B /r X where r A , r B and r X are the ionic radii of the corresponding ions [22] . Perovskite structure is likely to form when t falls in the approximate range of 0.8-1.1 and μ in the range of 0.4-0.9 [2,[23][24][25]. With these restrictions, only several inorganic cations such as Cs + or Rb + and organic cations such as methylammonium (MA + ), ethylammonium (EA + ), formamidinium (FA + ) meet the requirement as A + .…”

Design of Lead-Free Inorganic Halide Perovskites for Solar Cells via Cation-Transmutation

“…Previous statistic analysis of all the existing halide perovskites indicate that formability of perovskites requires 0.44 < μ < 0.90 and 0.81 < t < 1.11. 75 In the current double-perovskite A 2 M + M 3+ X VII 6 , one can define the effective t eff and μ eff as follows:…”

Finding New Perovskite Halides via Machine Learning

“…We started with the ABX 3 perovskite halide formability dataset used by Li et al (2008) consisting of 186 labeled compounds. From this dataset, five compounds (viz., KSmCl 3 , CsGeCl 3 , LiCoBr 3 , KCoBr 3 , and KCoI 3 ) were omitted since the bond valence features were not available for these compounds.…”