Zhou Yunxi, Li Junze, Fang Chen, Ma Jiaqi, Li Lu, Li Dehui
School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China.
School of Optical and Electronic Information and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China.
J Phys Chem Lett. 2021 Apr 8;12(13):3387-3392. doi: 10.1021/acs.jpclett.1c00295. Epub 2021 Mar 31.
Two-dimensional (2D) perovskites are an emerging class of layered materials with unique optoelectronic properties. To date, most 2D perovskites with Ruddlesden-Popper (RP) phase reported are organic- inorganic hybrid perovskites with long organic spacers. Here, we report a high-quality all-inorganic 2D perovskite, CsPbICl, synthesized by an aqueous method. The as-synthesized perovskite crystals exhibit large in-plane emission and reflection optical anisotropy. The maximum in-plane linear dichroic ratio is up to 9.6 for exciton emission and 2.0 for reflection at 77 K. The large in-plane optical anisotropy may be ascribed to the strong electron-phonon interaction-induced lattice distortion. The large optical anisotropy enables us to construct a polarization-sensitive photodetector based on this perovskite, for which the linear dichroic ratio of photoresponse is about 1.2. Our study provides an alternative avenue to achieve in-plane optical anisotropy in an isotropy structure and thus would be of great importance for polarization-associated applications.
二维（2D）钙钛矿是一类新兴的具有独特光电特性的层状材料。迄今为止，报道的大多数具有Ruddlesden-Popper（RP）相的二维钙钛矿是具有长有机间隔基的有机-无机杂化钙钛矿。在此，我们报道了一种通过水相法合成的高质量全无机二维钙钛矿CsPbICl。所合成的钙钛矿晶体表现出较大的面内发射和反射光学各向异性。在77 K时，激子发射的最大面内线性二向色比高达9.6，反射的最大面内线性二向色比为2.0。较大的面内光学各向异性可能归因于强电子-声子相互作用诱导的晶格畸变。这种大的光学各向异性使我们能够基于这种钙钛矿构建一个偏振敏感光电探测器，其光响应的线性二向色比约为1.2。我们的研究为在各向同性结构中实现面内光学各向异性提供了一条替代途径，因此对于与偏振相关的应用具有重要意义。
