Non-Centrosymmetric Chiral Structures for Hybrid Bismuth Halides With Stable Self-Driven X-Ray Detection

• Published in: IEEE electron device letters Vol. 45; no. 8; pp. 1441 - 1444
• Main Authors: Lei, Yutian, Li, Yumin, Peng, Guoqiang, Xu, Youkui, Wang, Haoxu, Fan, Hengzhong, Zhang, Yongsheng, Ci, Zhipeng, Li, ZhenHua, Wang, Qian, Jin, Zhiwen
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-08-2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bismuth halides; bulk photovoltaic effect; Chiral-nonpolar; Crystallization; Crystals; Electric fields; Electron clouds; Energy consumption; Halides; Heterostructures; metal halide; Metals; Performance evaluation; Photovoltaic effect; self-driven; Sensitivity; Thermal stability; X ray detectors; X ray irradiation; X-ray detection
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2024.3417437

Self-driving X-ray detectors have the advantages of low energy consumption, portability, and light weight. However, a complex heterostructure system must be constructed to generate a built-in electric field capable of driving carriers in many scenario. Here, we have pioneered the consideration of spatially breaking the symmetry of crystals, thereby giving them the ability to self-drive carriers, known as the bulk photovoltaic effect (BPVE). Specifically, (<inline-formula> <tex-math notation="LaTeX">{R}/{S} </tex-math></inline-formula>-MPZ)<inline-formula> <tex-math notation="LaTeX">^{{2}+} </tex-math></inline-formula> (<inline-formula> <tex-math notation="LaTeX">{R}/{S} </tex-math></inline-formula>-MPZ <inline-formula> <tex-math notation="LaTeX">={R}/ </tex-math></inline-formula> S-2-Methylpiperazine) chiral ions were introduced to deinduce the crystallization of (<inline-formula> <tex-math notation="LaTeX">{R}/{S} </tex-math></inline-formula>-MPZ)BiI5 in the non-centrosymmetric P<inline-formula> <tex-math notation="LaTeX">2_{{1}} 2_{{1}} 2_{{1}} </tex-math></inline-formula> space group. In this framework, the position of the electron cloud in real space is displaced by X-ray irradiation, resulting in self-driving behavior. As a result, our X-ray detectors exhibit a sensitivity of <inline-formula> <tex-math notation="LaTeX">54~\mu </tex-math></inline-formula>C Gy<inline-formula> <tex-math notation="LaTeX">_{\text {air}}^{-{1}} </tex-math></inline-formula> cm<inline-formula> <tex-math notation="LaTeX">^{-{2}} </tex-math></inline-formula> and an ultralow detection limit of 18.4 nGyair s<inline-formula> <tex-math notation="LaTeX">^{-{1}} </tex-math></inline-formula> under zero bias.<inline-formula> <tex-math notation="LaTeX">^{^{^{}}} </tex-math></inline-formula> In addition, they feature long-term stability over half a year and impressive imaging performance.