Chiral europium halides with high-performance magnetic field tunable red circularly polarized luminescence at room temperature
Xinyi Niu, Yang Li, Haolin Lu, Zhaoyu Wang, Yunxin Zhang, Tianyin Shao, Hebin Wang, Sehrish Gull, Bing Sun, Hao‐Li Zhang, Yongsheng Chen, Kai Wang, Yaping Du, Guankui Long
Abstract
Chiral organic-inorganic hybrid metal halides as promising circularly polarized luminescence (CPL) emitter candidates hold great potential for high-definition displays and future spin-optoelectronics. The recent challenge lies primarily in developing high-performance red CPL emitters. Here, coupling the f-f transition characteristics of trivalent europium ions (Eu3+) with chirality, we construct the chiral Eu-based halides, (R/S-3BrMBA)3EuCl6, which exhibit strong and predictable red emission with large photoluminescence quantum yield (59.8%), narrow bandwidth (≈2 nm), long lifetime (≈2 ms), together with large dissymmetry factor |glum| of 1.84 × 10−2. Compared with the previously reported chiral metal halides, these chiral Eu-based halides show the highest red CPL brightness. Furthermore, the degree of photoluminescence polarization in (R/S-3BrMBA)3EuCl6 can be manipulated by the external magnetic field. Particularly, benefiting from the field-generated Zeeman splitting and spin mixing at exciton states, an anomalously positive magneto-photoluminescence was observed at room temperature. This work provides an efficient strategy for constructing both high-performance and pure-red CPL emitters. It also opens the door for chiral rare-earth halides toward chiral optoelectronic and spintronic applications. Chiral organic-inorganic perovskites are promising materials for circularly polarized luminescence. Here the authors present chiral europium halides leading to red circularly polarized luminescence with large dissymmetry factor and strong magneto-chiroptical properties.