Biexcitons in 2D (iso-BA) 2 PbI 4 perovskite crystals

Nanophotonics

article

Wancai Li¹  Jiaqi Ma¹  Haizhen Wang²  Chen Fang¹  Hongmei Luo²  Dehui Li³ 

[1] School of Optical and Electronic Information, Huazhong University of Science and Technology;Department of Chemical and Materials Engineering, New Mexico State University;School of Optical and Electronic Information and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology

关键词: biexcitons;    quantum wells;    optical anisotropy;    2D perovskites;   

DOI  :  10.1515/nanoph-2019-0528

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Two-dimensional (2D) organic-inorganic hybrid perovskites have attracted growing attention recently due to their naturally formed quantum-well structure, unique photoelectric properties and better environmental stability compared to three-dimensional perovskites. The reduced screening and enhanced Coulomb interaction in 2D perovskites result in the formation of excitonic complexes. While the properties of free excitons have been well investigated, studies on biexcitons remain elusive. Here, we report on the biexcitons in 2D (iso-BA) 2 PbI 4 (BA=C 4 H 9 NH 3 ) crystals. The biexciton emission can be observed under a very low excitation power density of 6.4 W/cm 2 at 78 K. The biexciton exhibits a large biexciton binding energy of 46 meV due to the large exciton binding energy of (iso-BA) 2 PbI 4 . Furthermore, the biexcitons exhibit a favorable polarization orientation, resulting in different anisotropy between biexcitons and excitons. Our findings would motivate more studies on biexcitons in 2D perovskites and pave the way for exploiting the many-body physics for biexciton lasing and optical storage devices.

【 授权许可】

CC BY