Liu Xixia, Huang Tang Jiao, Zhang Liuyang, Tang Baoshan, Zhang Nengduo, Shi Diwen, Gong Hao
Department of Materials Science and Engineering, National University of Singapore, 117576, Singapore, Singapore.
Singapore Institute of Manufacturing Technology (SIMTech), 2 Fusionopolis Way, # 08-04, 138634, Singapore, Singapore.
Chemistry. 2018 Apr 3;24(19):4991-4998. doi: 10.1002/chem.201800062. Epub 2018 Mar 15.
Lead halide perovskites have attracted striking attention recently, due to their appealing properties. However, toxicity and stability are two main factors restricting their application. In this work, a less toxic and highly stable Pd-based hybrid perovskite was experimentally synthesized, after exploring different experimental conditions. This new hybrid organic-inorganic perovskite (CH NH ) PdBr was found to be an orthorhombic crystal (Cmce, Z=4) with lattice parameters a=8.00, b=7.99, c=18.89 Å. The Cmce symmetry and lattice parameters were confirmed using Pawley refinement and the atoms positions were confirmed based on DFT calculation. This perovskite compound was determined to be a p-type semiconductor, with a resistivity of 102.9 kΩ cm, a carrier concentration of 3.4 ×10 cm , and a mobility of 23.4 cm (V s) . Interestingly, XRD and UV/Vis measurements indicated that the phase of this new perovskite was maintained with an optical gap of 1.91 eV after leaving in air with a high humidity of 60 % for 4 days, and unchanged for months in N atmosphere; much more stable than most existing organic-inorganic perovskites. The synthesis and various characterizations of this work further the understanding of this (CH NH ) PdBr organic-inorganic hybrid perovskite material.
卤化铅钙钛矿因其具有吸引力的特性，近来备受关注。然而，毒性和稳定性是限制其应用的两个主要因素。在这项工作中，在探索了不同的实验条件之后，通过实验合成了一种毒性较小且高度稳定的钯基杂化钙钛矿。发现这种新型有机-无机杂化钙钛矿（CH₃NH₃）₂PdBr₄是一种正交晶体（Cmce，Z = 4），晶格参数a = 8.00，b = 7.99，c = 18.89 Å。使用Pawley精修确认了Cmce对称性和晶格参数，并基于密度泛函理论（DFT）计算确定了原子位置。这种钙钛矿化合物被确定为p型半导体，电阻率为102.9 kΩ·cm，载流子浓度为3.4×10¹⁶ cm⁻³，迁移率为23.4 cm²/（V·s）。有趣 的是，X射线衍射（XRD）和紫外可见（UV/Vis）测量表明，这种新型钙钛矿在60%的高湿度空气中放置4天后，其相保持不变，光学带隙为1.91 eV，在氮气气氛中几个月都没有变化；比大多数现有的有机-无机钙钛矿稳定得多。这项工作的合成及各种表征进一步加深了对这种（CH₃NH₃）₂PdBr₄有机-无机杂化钙钛矿材料的理解。
