Layered Perovskite (CH3NH3)2Pb(SCN)2I2 Single Crystals: Phase Transition and Moisture Stability

Yangyang Dang; Guokui Liu; Jiewu Song; Lingqiang Meng; Yajing Sun; Wenping Hu; Xutang Tao

doi:10.1021/acsami.0c09251

Layered Perovskite (CH₃NH₃)₂Pb(SCN)₂I₂ Single Crystals: Phase Transition and Moisture Stability

ACS Appl Mater Interfaces. 2020 Aug 19;12(33):37713-37721. doi: 10.1021/acsami.0c09251. Epub 2020 Aug 10.

Authors

Yangyang Dang^{1

2}, Guokui Liu³, Jiewu Song¹, Lingqiang Meng⁴, Yajing Sun², Wenping Hu², Xutang Tao¹

Affiliations

¹ State Key Laboratory of Crystal Materials & Institute of Crystal Materials, Shandong University, No. 27 Shanda South Road, Jinan 250100, P. R. China.
² Tianjin Key Laboratory of Molecular Optoelectronic Sciences & Department of Chemistry, School of Sciences, & Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin 300072, P. R. China.
³ School of Chemistry and Chemical Engineering, Linyi University, Linyi 276000, P. R. China.
⁴ Materials Interfaces Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, P.R. China.

PMID: 32814401
DOI: 10.1021/acsami.0c09251

Abstract

To study stability issues of three-dimensional perovskites, there is a strategy to introduce the thiocyanate ion (SCN^-) into CH₃NH₃PbI₃ (MAPbI₃) to solve these problems. Here, we report the bulk growth of layered perovskite MA₂Pb(SCN)₂I₂ single crystals by different growth methods in an ambient atmosphere. We also investigate the structural determination and refinements, band gap, and photoluminescence of MA₂Pb(SCN)₂I₂ single crystals. More importantly, the phase transition and stability of MA₂Pb(SCN)₂I₂ are systematically demonstrated. MA₂Pb(SCN)₂I₂ undergo the reversible single-crystal to single-crystal phase transition in the orthorhombic systems from the space group Pmmn (no. 59) to the space group Pmn2₁ (no. 31) at low temperature. Moreover, the temperature-dependent recovery behaviors of MA₂Pb(SCN)₂I₂ single crystals, powders, and thin films at high temperature are studied in detail. Besides, the moisture stability of MA₂Pb(SCN)₂I₂ is described when exposed to moisture condition by the experiment and theoretical calculations. It would be interesting to not only conduct a comprehensive study on the crystal structures and the phase transition processes of layered perovskites but also provide guidance for further optoelectronic applications of these perovskite materials.

Keywords: crystal growth; crystal structure; layered perovskite; phase transition; stability.