Lehmann Frederike, Franz Alexandra, Többens Daniel M, Levcenco Sergej, Unold Thomas, Taubert Andreas, Schorr Susan
Helmholtz-Zentrum Berlin für Materialien und Energie Hahn-Meitner Platz 1 14109 Berlin Germany
University of Potsdam, Institute of Chemistry Karl-Liebknecht-Straße 24-25 14476 Potsdam OT Golm Germany.
RSC Adv. 2019 Apr 9;9(20):11151-11159. doi: 10.1039/c8ra09398a.
By using synchrotron X-ray powder diffraction, the temperature dependent phase diagram of the hybrid perovskite tri-halide compounds, methyl ammonium lead iodide (MAPbI, MA = CHNH ) and methyl ammonium lead bromide (MAPbBr), as well as of their solid solutions, has been established. The existence of a large miscibility gap between 0.29 ≤ ≤ 0.92 (±0.02) for the MAPb(I Br ) solid solution has been proven. A systematic study of the lattice parameters for the solid solution series at room temperature revealed distinct deviations from Vegard's law. Furthermore, temperature dependent measurements showed that a strong temperature dependency of lattice parameters from the composition is present for iodine rich compositions. In contrast, the bromine rich compositions show an unusually low dependency of the phase transition temperature from the degree of substitution.
通过使用同步加速器X射线粉末衍射，已经建立了混合钙钛矿三卤化物化合物甲基碘化铅铵（MAPbI，MA = CH₃NH₃）、甲基溴化铅铵（MAPbBr）及其固溶体的温度相关相图。已证明对于MAPb(IₓBr₁₋ₓ) 固溶体，在0.29 ≤ x ≤ 0.92 (±0.02) 之间存在较大的混溶间隙。对室温下固溶体系列晶格参数的系统研究表明，其明显偏离了维加德定律。此外，温度相关测量表明，对于富碘成分，晶格参数随成分的温度依赖性很强。相比之下，富溴成分的相变温度随取代度的依赖性异常低。
