Towards superior X-ray detection performance of two-dimensional halide perovskite crystals by adjusting the anisotropic transport behavior
Towards superior X-ray detection performance of two-dimensional halide perovskite crystals by adjusting the anisotropic transport behavior
复制标题
通过调整各向异性传输行为实现二维卤化物钙钛矿晶体的卓越 X 射线检测性能
DOI：
10.1039/d1ta02918e
复制
发表时间：
2021-05-12
影响因子：
11.9
通讯作者：
Xu, Yadong
中科院分区：
文献类型：
--
作者：
Xiao, Bao;Sun, Qihao;Xu, Yadong
二维(2D)有机-无机杂化卤化物钙钛矿由于其与三维(3D)钙钛矿相比具有的可调性和优异的稳定性而在电子学和光电子学领域引起了广泛的关注。在这里，我们报道了两种有机阳离子(直丁胺(BA)和支化异丁胺(I-BA))定制的CsPbBr3晶体，即(BA)(2)CsPb2Br7和(i-BA)(2)CsPb2Br7。系统地研究了有机阳离子的可调各向异性结构、光电性质和X射线探测性能。通过缩短间隔基阳离子从BA到I-BA，降低了二维钙钛矿晶体的各向异性程度，这可能归因于相邻有机阳离子之间的电子耦合增强导致层间距和势垒高度减小。特别是，基于沿ab平面的(BA)(2)CsPb2Br7晶体的器件在2.53V mm(-1)的相对较低的电场下表现出高达13.26mCGy1-1 cm(-2)的X射线灵敏度，这是因为多量子阱结构限制了ab平面内的电荷载流子传输，从而导致了高效的电荷收集。同时，在高剂量率(278.4 mGyS(-1))下，获得了良好的长期工作稳定性。我们期待这些发现将有助于Ruddlesden-Popper钙钛矿材料的发展，为未来的研究和应用提供帮助。
Two-dimensional (2D) organic-inorganic hybrid halide perovskites have recently attracted extensive attention for electronic and optoelectronic applications due to their tunable properties and superior stability compared with their three-dimensional (3D) counterparts. Here, we report two kinds of organic cation (linear butylamine (BA) and branched isobutylamine (i-BA)) tailored CsPbBr3 crystals, namely (BA)(2)CsPb2Br7 and (i-BA)(2)CsPb2Br7, grown by the temperature-cooling method. The organic cations' adjustable anisotropic structure, optoelectronic properties and X-ray detection performance have been systematically investigated. By shortening the spacer cation from BA to i-BA, the degree of anisotropy in 2D perovskite crystals is decreased, which may be ascribed to the reduced interlayer distance and barrier height resulting from the enhanced electronic coupling between neighboring organic cations. In particular, the device based on the (BA)(2)CsPb2Br7 crystal along the ab plane exhibits superior X-ray sensitivity up to 13.26 mC Gy(-1) cm(-2) at a relatively low electric field of 2.53 V mm(-1), owing to the multiple quantum well structure that restricts the charge carrier transport within the ab plane resulting in efficient charge collection. Simultaneously, a superior long-term working stability is obtained under a high X-ray dose rate of 278.4 mu Gy s(-1). We anticipate that these findings will be helpful for the development of Ruddlesden-Popper perovskites for future research and applications.