Du Qin, Zhu Cheng, Yin Zixi, Na Guangren, Cheng Chuantong, Han Ying, Liu Na, Niu Xiuxiu, Zhou Huanping, Chen Hongda, Zhang Lijun, Jin Shengye, Chen Qi
Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, Advanced Materials Experimental Center, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, P.R. China.
State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P.R. China.
ACS Nano. 2020 May 26;14(5):5806-5817. doi: 10.1021/acsnano.0c00907. Epub 2020 Apr 23.
Organic-inorganic hybrid halide perovskites (ABX), especially layered 2D perovskites, have been recognized as promising semiconductors due to their tunable crystal structure and unique optoelectronic properties. A-site cations, as spacers, allow various metal halide assemblies, but the stacking pattern and the influence of their collective behavior on the properties of the resultant materials remain ambiguous. Here, the cation-stacking effects in the 2D perovskite single crystals, with a focus on the electron-phonon interaction, are investigated. We reveal the different photoluminescence from the surface region and the interior of the crystal, which is due to the residual strain induced by A-site cation stacking. We also examine the cation-stacking effects on the electron-phonon interaction, which is further employed to tailor the optoelectronic properties of the resultant 2D crystals. By reducing the microstrain, we reduce the electron-phonon coupling to improve the mobility and their stability against electric field in the corresponding crystals. Our study suggests a way to manipulate the optoelectronic properties in 2D perovskite materials by rational design of cation stacking.
有机-无机杂化卤化物钙钛矿（ABX），尤其是层状二维钙钛矿，因其可调节的晶体结构和独特的光电特性而被视为有前景的半导体。A位阳离子作为间隔物，允许形成各种金属卤化物组装体，但它们的堆积模式及其集体行为对所得材料性能的影响仍不明确。在此，我们研究二维钙钛矿单晶中的阳离子堆积效应，重点关注电子-声子相互作用。我们揭示了晶体表面区域和内部不同的光致发光现象，这是由A位阳离子堆积引起的残余应变所致。我们还研究了阳离子堆积对电子-声子相互作用的影响，并进一步利用该影响来调控所得二维晶体的光电特性。通过降低微应变，我们减少了电子-声子耦合，以提高相应晶体中的迁移率及其对电场的稳定性。我们的研究提出了一种通过合理设计阳离子堆积来调控二维钙钛矿材料光电特性的方法。
