Choi Yong Kyu, Heo Jin Hyuck, Hong Ki-Ha, Im Sang Hyuk
Department of Chemical and Biological Engineering, Korea University 145 Anam-ro, Seongbuk-gu Seoul 02841 Korea
Department of Materials Science and Engineering, Hanbat National University 125 Dongseo-daero, Yuseong-Gu Daejeon 34158 Korea
RSC Adv. 2020 May 6;10(30):17724-17730. doi: 10.1039/d0ra00787k. eCollection 2020 May 5.
Structure engineering of trivalent metal halide perovskites (MHPs) such as ASbX (A = a monovalent cation such as methyl ammonium (MA), cesium (Cs), and formamidinium (FA) and X = a halogen such as I, Br, and Cl) is of great interest because a two dimensional (2D) layer structure with direct bandgap has narrower bandgap energy than a zero dimensional (0D) dimer structure with indirect bandgap. Here, we demonstrated 2D layer structured FACsSbICl MHP by dual-site (A and X site) mixing. Thanks to the lattice-symmetry change by I-Cl mixed halide, the shortest ionic radius of Cs, and the lower solution energy due to dual-site mixing, the FACsSbICl MHP had 2D layer structure and thereby the MHP solar cells exhibited improved short-circuit current density.
诸如 ASbX（A = 一价阳离子，如甲基铵（MA）、铯（Cs）和甲脒（FA）；X = 卤素，如 I、Br 和 Cl）等三价金属卤化物钙钛矿（MHP）的结构工程备受关注，因为具有直接带隙的二维（2D）层状结构比具有间接带隙的零维（0D）二聚体结构具有更窄的带隙能量。在此，我们通过双位点（A 和 X 位点）混合展示了二维层状结构的 FACsSbICl MHP。由于 I-Cl 混合卤化物引起的晶格对称性变化、Cs 的最短离子半径以及双位点混合导致的较低溶液能量，FACsSbICl MHP 具有二维层状结构，因此 MHP 太阳能电池表现出改善的短路电流密度。
