Temperature and pressure-induced excitation-dependent emissions in zero-dimensional hybrid metal halides with mixed halogens

Bin Xu; Qian Li; Jiang Han; Zhongwei Chen; Zhishan Luo; Yulin Chen; Zewei Quan

doi:10.1063/5.0205703

Temperature and pressure-induced excitation-dependent emissions in zero-dimensional hybrid metal halides with mixed halogens

J Chem Phys. 2024 May 21;160(19):191101. doi: 10.1063/5.0205703.

Authors

Bin Xu¹, Qian Li², Jiang Han¹, Zhongwei Chen¹, Zhishan Luo¹, Yulin Chen¹, Zewei Quan¹

Affiliations

¹ Department of Chemistry, Southern University of Science and Technology (SUSTech), Shenzhen, Guangdong 518055, China.
² School of Physics Science and Information Technology, Shandong Key Laboratory of Optical Communication Science and Technology, Liaocheng University, Liaocheng, Shandong 252000, China.

PMID: 38747437
DOI: 10.1063/5.0205703

Abstract

Zero-dimensional (0D) hybrid metal halides (HMHs) have emerged as a promising platform for exploring excitation-dependent multicolor luminescent materials owing to their diverse crystal structures and chemical compositions. Nevertheless, understanding the mechanism behind excitation-dependent emissions (EDEs) in 0D HMHs and achieving precise modulation remains challenging. In this work, the delicate regulations on the EDE of 0D (DMEDABr)4SnBr3I3 (DMEDA: N, N'-dimethylethylenediamine) with mixed halogens are achieved under low temperature and high pressure, respectively. The inhomogeneous halogen occupation at the atomic scale leads to the formation of Br-rich and I-rich SnX6 (X = Br, I) octahedra, which act as distinct luminescent centers upon photoexcitation. At low temperatures, the narrowed photoluminescence spectra could distinguish the individual emissions from different luminescent centers, resulting in a pronounced EDE of (DMEDABr)4SnBr3I3. In addition, the contraction and distortion of the luminescent SnX6 (X = Br, I) centers at high pressure further result in different degrees of emission shifts, giving rise to the gradual emergence and disappearance of EDE. This work elucidates the underlying mechanism of EDE in 0D HMHs and highlights the crucial role of halogens in determining the optical properties of metal halides.