Bright Green Emission from Self-Trapped Excitons Triggered by Sb3+ Doping in Rb4CdCl6

• Published in: Chemistry of materials Vol. 34; no. 12; pp. 5717 - 5725
• Main Authors: Jin, Jiance, Peng, Yinghui, Xu, Yuting, Han, Kai, Zhang, Anran, Yang, Xiao-Bao, Xia, Zhiguo
• Format: Journal Article
• Language: English
• Published: American Chemical Society 28.06.2022
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/acs.chemmater.2c01254

Sb3+ with stereochemically active lone pair 5s 2 electrons is overwhelming in the doping engineering of the luminescent metal halides, and it usually leads to extrinsic self-trapped excitons (STEs) with tunable emissions. However, the photoluminescence enhancement mechanism of Sb3+ doped metal halides compared to the pristine host remains unclear. Herein, we doped Sb3+ into all-inorganic non-emissive Rb4CdCl6, realizing bright green emission peaking at 525 nm with a photoluminescence quantum yield of 70.2%. A comparison of Raman spectra, as well as the Debye temperature, was utilized to elucidate the STEs mechanism, verifying that the doping of Sb3+ softens the structural lattice. Thus, strong electron–phonon interactions enable highly efficient photoluminescence originating from STEs emission in Rb4CdCl6:Sb3+. This work demonstrates solid evidence that the efficient emissions of metal halides can be triggered by Sb3+ doping, and the design principle involved will guide the future studies for emerging luminescence material exploration.