Boosting the Performance of Self-Powered CsPbCl3-Based UV Photodetectors by a Sequential Vapor-Deposition Strategy and Heterojunction Engineering
Boosting the Performance of Self-Powered CsPbCl3-Based UV Photodetectors by a Sequential Vapor-Deposition Strategy and Heterojunction Engineering
复制标题
通过顺序气相沉积策略和异质结工程提高自供电 CsPbCl3 紫外光电探测器的性能
DOI：
10.1021/acsami.1c15013
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发表时间：
2021
影响因子：
9.5
通讯作者：
Liu Xingyue
中科院分区：
文献类型：
--
作者：
Zhan Xiaobin;Zhang Xuning;Liu Zhiyong;Chen Chen;Kong Lingxian;Jiang Shulan;Xi Shuang;Liao Guanglan;Liu Xingyue
全无机 CsPbCl3 钙钛矿在紫外 (UV) 检测中由于其紫外匹配光学带隙、超高紫外稳定性和优异的固有光电特性而引起越来越多的关注。几乎所有报道的CsPbCl3光电探测器都采用CsPbCl3纳米结构或微结构作为敏感元件，而基于CsPbCl3多晶薄膜的自供电光电探测器由于前体溶解度差而很少被研究。在此，首次展示了一种新颖的连续气相沉积技术来制造 CsPbCl3 多晶薄膜。获得了具有优异光学、电子和形貌特征的高质量CsPbCl3薄膜。基于CsPbCl3薄膜的自供电光电探测器无需任何电荷传输层，表现出较高的紫外探测性能。进一步引入薄的p型PbS缓冲层来钝化CsPbCl3层的表面缺陷，并通过形成II型异质结来降低界面能垒，从而有助于更快的空穴提取速率和抑制暗电流水平。性能最佳的器件可实现 1.92 μs 的超快响应时间、2.22 × 105 的超高开/关比以及 0 V 偏压下 375 nm 紫外照明下 0.22 A/W 的响应度。这一综合性能是迄今为止报道的所有 CsPbCl3 光电探测器中最好的。所制备的光电探测器还具有出色的紫外线照射能力和在环境空气中的长期耐用性。此外，还制作了大面积、均匀的625像素UV图像传感器，并具有突出的成像能力。我们的工作为基于 CsPbCl3 的光电子产品的可扩展生产开辟了一条新途径。
All-inorganic CsPbCl3perovskite in ultraviolet (UV) detection is drawing increasing interest owing to its UV-matchable optical band gap, ultrahigh UV stability, and superior inherent optoelectronic properties. Almost all of the reported CsPbCl3photodetectors employ CsPbCl3nano- or microstructures as sensitive components, while CsPbCl3polycrystalline film-based self-powered photodetectors are rarely studied on account of the terrible precursor solubility. Herein, a novel sequential vapor-deposition technique is demonstrated to fabricate CsPbCl3polycrystalline film for the first time. High-quality CsPbCl3films with excellent optical, electronic, and morphological features are obtained. A self-powered photodetector based on the CsPbCl3film is constructed without any charge transport layer, showing a high UV detection performance. A thin p-type PbS buffer layer is further introduced to passivate the surface defects of the CsPbCl3layer and decrease the interfacial energy barrier by forming a type-II heterojunction, contributing to a faster hole extraction rate and a suppressed dark current level. The best-performing device achieves an ultrafast response time of 1.92 μs, an ultrahigh on/off ratio of 2.22 × 105, and a responsivity of 0.22 A/W upon 375 nm UV illumination at 0 V bias. This comprehensive performance is the best among all of the CsPbCl3photodetectors reported to date. The as-prepared photodetectors also present an eminent UV irradiation and long-term durability in ambient air. Furthermore, a large-area and uniform 625-pixel UV image sensor is fabricated and attains a prominent imaging capability. Our work opens a new avenue for the scalable production of CsPbCl3-based optoelectronics.