Tang Ying, Yin Chunyang, Jing Qiang, Zhang Chunfeng, Yu Zhi-Gang, Lu Zhenda, Xiao Min, Wang Xiaoyong
National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China.
Nano Lett. 2022 Apr 13;22(7):2907-2914. doi: 10.1021/acs.nanolett.2c00079. Epub 2022 Apr 1.
The quantum-confinement effect profoundly influences the exciton energy-level structures and recombination dynamics of semiconductor nanostructures but remains largely unexplored in traditional one-dimensional nanowires mainly due to their poor optical qualities. Here, we show that in defect-tolerant perovskite material of highly luminescent CsPbBr nanowires, the exciton's center-of-mass motion perpendicular to the axial direction is severely confined. This is reflected in the two sets of photoluminescence spectra emitted from a single CsPbBr nanowire, each of which consists of doublet peaks with linear polarizations perpendicular and parallel to the axial direction. Moreover, different exciton states can be mixed by the Rashba spin-orbit coupling effect, resulting in two single photoluminescence peaks with linear polarizations both along the nanowire axis. The above findings mark the emergence of an ideal platform for the exploration of intrinsic one-dimensional exciton photophysics and optoelectronics, thus bridging the long-missing research gap between the well-studied two- and zero-dimensional semiconductor nanostructures.
量子限制效应深刻影响着半导体纳米结构的激子能级结构和复合动力学，但在传统的一维纳米线中，由于其光学质量较差，这一效应在很大程度上仍未得到探索。在此，我们表明，在高发光性的CsPbBr纳米线这种容错钙钛矿材料中，激子垂直于轴向的质心运动受到严重限制。这反映在从单个CsPbBr纳米线发射的两组光致发光光谱中，每组光谱都由具有垂直和平行于轴向的线性偏振的双峰组成。此外，不同的激子态可通过Rashba自旋 - 轨道耦合效应混合，从而产生两个沿纳米线轴均具有线性偏振的单光致发光峰。上述发现标志着一个用于探索本征一维激子光物理和光电子学的理想平台的出现，从而弥合了在充分研究的二维和零维半导体纳米结构之间长期缺失的研究空白。
