Guo Jie, Fu Yuhao, Lu Min, Zhang Xiaoyu, Kershaw Stephen V, Zhang Jia, Luo Shulin, Li Yanxiu, Yu William W, Rogach Andrey L, Zhang Lijun, Bai Xue
State Key Laboratory of Integrated Optoelectronics and College of Electronic Science and Engineering Jilin University Changchun 130012 China.
State Key Laboratory of Superhard Materials and College of Physics Jilin University Changchun 130012 China.
Adv Sci (Weinh). 2020 Jun 17;7(15):2000930. doi: 10.1002/advs.202000930. eCollection 2020 Aug.
One-dimensional semiconductor nanostructures have already been used for a variety of optoelectronic applications. Metal halide perovskites have emerged in recent years as promising high-performance optoelectronic materials, but reports on 1D nanorods (NRs) of all-inorganic halide perovskites are still scarce. This work demonstrates a synthetic strategy toward cesium-based inorganic perovskite NRs by exploiting composition-controlled crystal phase engineering. It is accomplished for Cd-rich mixed-cation CsPb Cd Br nanocrystals, where the initial 1D hexagonal perovskite phase drives the growth of the 1D NRs, as supported by first-principles calculations. The band gaps of the resulting NRs are tunable by varying the Cd-content, and the highly uniform CsPbCdBr NRs (with an average length of 84 nm and width of 16 nm) exhibit a true blue-color emission centered at 460 nm, with a high quantum yield of 48%. Moreover, this work also demonstrates the tunability of the Fermi levels in the films made of CsPb Cd Br alloyed nanocrystals, where samples with highest Cd content show an increase of the electron concentration and a related increase in the conductivity.
一维半导体纳米结构已被用于各种光电子应用。金属卤化物钙钛矿近年来已成为有前景的高性能光电子材料，但关于全无机卤化物钙钛矿的一维纳米棒（NRs）的报道仍然很少。这项工作通过利用成分控制的晶相工程展示了一种合成铯基无机钙钛矿NRs的策略。这是通过富镉混合阳离子CsPbCdBr纳米晶体实现的，其中初始的一维六方钙钛矿相驱动一维NRs的生长，第一性原理计算支持了这一点。所得NRs的带隙可通过改变镉含量来调节，高度均匀的CsPbCdBr NRs（平均长度为84nm，宽度为16nm）在460nm处呈现出真正的蓝色发射，量子产率高达48%。此外，这项工作还展示了由CsPbCdBr合金化纳米晶体制成的薄膜中费米能级的可调性，其中镉含量最高的样品显示出电子浓度的增加以及相关的电导率增加。
