Spin-configuration of emission states in zero-dimensional metal halides

• Published in: National science review Vol. 12; no. 5; p. nwae180
• Main Authors: Kuang, Zhiyuan, Huang, Xinyu, Wang, Xing, Wang, Chengcheng, Wang, Xinrui, Huang, Wei, Peng, Qiming, Wang, Jianpu
• Format: Journal Article
• Language: English
• Published: China Oxford University Press 01.05.2025
• Subjects: RESEARCH ARTICLE; dual-peak emission; zero-dimensional metal-halides; magneto-optical study; spin-configuration
• ISSN: 2095-5138; 2053-714X; 2053-714X
• DOI: 10.1093/nsr/nwae180

Understanding the spin-configuration of excited states in a luminescent material is essential for tailoring its properties for many applications such as light-emitting diodes and spin-optoelectronic devices. Zero-dimensional organic-inorganic metal halide (0D-OIMH) materials have demonstrated remarkable potential in diverse applications owing to their captivating optoelectronic characteristics. However, the electronic structure and spin-configuration of the frequently observed dual-peak emission in these materials remains a subject of intensive debate. In this study, we employ low-temperature magneto-optical measurements to investigate the excited state structure of a representative 0D-OIMH, namely (Bmpip)2SnBr4. The spin-configurations of the dark and bright states are clearly elucidated by measuring the magneto-polarization of the emissions. Our results reveal that the high-energy peak arises from bright excited states within a higher energy band, whilst the low-energy peak originates from a combination of triplet-bright states and singlet-dark states. These findings provide an unambiguous understanding of the exciton structures of the distinctive 0D-OIMHs.