Experimentelle Physik 2, Technische Universität Dortmund , 44227 Dortmund, Germany.
Rzhanov Institute of Semiconductor Physics, Siberian Branch of Russian Academy of Sciences , 630090 Novosibirsk, Russia.
Nano Lett. 2017 Oct 11;17(10):6177-6183. doi: 10.1021/acs.nanolett.7b02827. Epub 2017 Sep 7.
The optical properties of colloidal cesium lead halide perovskite (CsPbBr) nanocrystals are examined by time-resolved and polarization-resolved spectroscopy in high magnetic fields up to 30 T. We unambiguously show that at cryogenic temperatures the emission is dominated by recombination of negatively charged excitons with radiative decay time of 300 ps. The additional long-lived emission, which decay time shortens from 40 down to 8 ns and in which the decay time shortens and relative amplitude increases in high magnetic fields, evidences the presence of a dark exciton. We evaluate g-factors of the bright exciton g = +2.4, the electron g = +2.18, and the hole g = -0.22.
通过在高达 30 T 的高磁场中进行时间分辨和偏振分辨光谱学研究，研究了胶体铯铅卤钙钛矿（CsPbBr）纳米晶体的光学性质。我们明确地表明，在低温下，发射主要是由带负电荷激子的复合与 300 ps 的辐射衰减时间决定的。额外的长寿命发射，其衰减时间从 40 缩短到 8 ns，并且在高磁场中衰减时间缩短且相对幅度增加，证明了暗激子的存在。我们评估了亮激子 g = +2.4、电子 g = +2.18 和空穴 g = -0.22 的 g 因子。
