Liu Xin, Xu Meng, Hao Yingying, Fu Jinghua, Wang Fangbao, Zhang Binbin, Bennett Stephanie, Sellin Paul, Jie Wanqi, Xu Yadong
State Key Laboratory of Solidification Processing, MIIT Key Laboratory of Radiation Detection Materials and Devices, & School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, China.
Department of Physics, University of Surrey, Guildford GU2 7XH, U.K.
ACS Appl Mater Interfaces. 2021 Apr 7;13(13):15383-15390. doi: 10.1021/acsami.1c00174. Epub 2021 Mar 25.
Compared with the widely reported MAPbBr single crystals, formamidinium-based (FA-based) hybrid perovskites FAPbBr (FPB) with superior chemical and structure stability are expected to be more efficient and perform as more reliable radiation detectors at room temperature. Here, we employ an improved inverse temperature crystallization method to grow FPB bulk single crystals, where issues associated with the retrograde solubility behavior are resolved. A crystal growth phase diagram has been proposed, and accordingly, growth parameters are optimized to avoid the formation of NHPbBr secondary phase. The resulting FPB crystals exhibit a high resistivity of 2.8 × 10 Ω·cm and high electron and hole mobility-lifetime products (μτ) of 8.0 × 10 and 1.1 × 10 cm·V, respectively. Simultaneously, the electron and hole mobilities (μ) are evaluated to be 22.2 and 66.1 cm·V·s, respectively, based on the time-of-flight technique. Furthermore, a Au/FPB SC/Au detector is constructed that demonstrates a resolvable gamma peak from 59.5 keV Am γ-rays at room temperature for the first time. An energy resolution of 40.1% is obtained at 30 V by collecting the hole signals. These results demonstrate the great potential of FAPbBr as a hybrid material for γ-ray spectroscopy and imaging.
与广泛报道的MAPbBr单晶相比，具有优异化学和结构稳定性的甲脒基（FA基）杂化钙钛矿FAPbBr（FPB）有望在室温下更高效且作为更可靠的辐射探测器发挥作用。在此，我们采用改进的逆温结晶法生长FPB块状单晶，解决了与逆向溶解度行为相关的问题。提出了晶体生长相图，并据此优化生长参数以避免形成NHPbBr次生相。所得的FPB晶体表现出2.8×10Ω·cm的高电阻率以及分别为8.0×10和1.1×10cm·V的高电子和空穴迁移率-寿命乘积（μτ）。同时，基于飞行时间技术评估电子和空穴迁移率（μ）分别为22.2和66.1cm·V·s。此外，首次构建了Au/FPB SC/Au探测器，其在室温下能分辨出来自59.5keV Amγ射线的γ峰。通过收集空穴信号，在30V时获得了40.1%的能量分辨率。这些结果证明了FAPbBr作为用于γ射线光谱学和成像的杂化材料具有巨大潜力。
