Kinetically Controlled Growth of Sub‐Millimeter 2D Cs 2 SnI 6 Nanosheets at the Liquid–Liquid Interface
Kinetically Controlled Growth of Sub‐Millimeter 2D Cs 2 SnI 6 Nanosheets at the Liquid–Liquid Interface
复制标题
亚毫米二维 Cs 2 SnI 6 纳米片在液-液界面处的动力学控制生长
DOI：
10.1002/smll.202006279
复制
发表时间：
2020
期刊：
影响因子：
13.3
通讯作者：
Lian, Jie
中科院分区：
文献类型：
--
作者：
Zhu, Weiguang;Shen, Junhua;Li, Mingxin;Yang, Kun;Bu, Wei;Sun, Yi‐Yang;Shi, Jian;Lian, Jie
Cs2 SnI 6钙钛矿具有优异的空气稳定性和高吸收系数，有望用于光伏和光电应用。然而，由于缺乏优化的合成方法来获得高质量的Cs2 SnI 6晶体，基于Cs2 SnI 6的器件性能仍然较低。本文报道了一种在液-液界面合成Cs_2SnI_6钙钛矿单晶的新方法。通过控制溶剂条件和Cs2 SnI 6在液-液界面处的过饱和度，可以从三维到二维生长具有可控几何形状的Cs2 SnI 6晶体，如八面体、金字塔、六边形和三角形纳米片。研究了高质量Cs_2SnI_6晶体复杂形状/几何结构的形成机理和动力学。独立的单晶2D纳米片可以制造成薄至25 nm，并且横向尺寸可以控制到亚毫米范围。高质量Cs2 SnI 62 D纳米片的电子特性也被表征，其特征在于具有35 cm 2 V − 1 s −1的高载流子迁移率的n型导电。高质量晶体的界面反应控制合成和对晶体生长的机理理解允许实现材料的合理设计，并且晶体生长的操纵可以有利于实现潜在功能应用的所需性质。
Cs2SnI6perovskite displays excellent air stability and a high absorption coefficient, promising for photovoltaic and optoelectronic applications. However, Cs2SnI6‐based device performance is still low as a result of lacking optimized synthesis approaches to obtain high quality Cs2SnI6crystals. Here, a new simple method to synthesize single crystalline Cs2SnI6perovskite at a liquid–liquid interface is reported. By controlling solvent conditions and Cs2SnI6supersaturation at the liquid–liquid interface, Cs2SnI6crystals can be obtained from 3D to 2D growth with controlled geometries such as octahedron, pyramid, hexagon, and triangular nanosheets. The formation mechanisms and kinetics of complex shapes/geometries of high quality Cs2SnI6crystals are investigated. Freestanding single crystalline 2D nanosheets can be fabricated as thin as 25 nm, and the lateral size can be controlled up to sub‐millimeter regime. Electronic property of the high quality Cs2SnI62D nanosheets is also characterized, featuring a n‐type conduction with a high carrier mobility of 35 cm2V−1s−1. The interfacial reaction‐controlled synthesis of high‐quality crystals and mechanistic understanding of the crystal growth allow to realize rational design of materials, and the manipulation of crystal growth can be beneficial to achieve desired properties for potential functional applications.