Ma Jingli, Xia Xiaochuan, Yan Su, Li Ying, Liang Wenqing, Yan Jingjing, Chen Xu, Wu Di, Li Xinjian, Shi Zhifeng
Key Laboratory of Materials Physics of Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, 75 Daxue Road, Zhengzhou 450052, China.
School of Microelectronics, Dalian University of Technology, Dalian 116023, China.
ACS Appl Mater Interfaces. 2021 Apr 7;13(13):15409-15419. doi: 10.1021/acsami.1c00387. Epub 2021 Mar 29.
Self-powered solar-blind ultraviolet (UV) photodetectors have drawn worldwide attention in recent years because of their important applications in military and civilian areas. In this study, a dual-source vapor codeposition technique was employed, for the first time, to prepare a nontoxic copper halide CsCuI, which was integrated with the β-GaO wafer to construct a type-II heterojunction for photodetection applications. By optimizing the annealing conditions, high-quality CsCuI films with dense morphology, high crystallinity, and a long carrier lifetime of 1.02 μs were acquired. Because of the high material integrity of CsCuI films and effective interfacial carrier transfer from CsCuI to β-GaO, a heterojunction device demonstrates a good solar-blind UV response property and operates at zero bias. Typically, the photodetector presents a low dark current (∼1.2 pA), a high solar-blind/UVA rejection ratio (∼1.0 × 10), a relatively fast photoresponse speed (37/45 ms), and a high photo-to-dark current ratio (∼5.1 × 10) at zero bias. Moreover, even after 12-h continuous working and 2-month storage without encapsulation in ambient air, the photodetection ability of the device can almost be maintained, demonstrating outstanding air stability. Our results suggest that nontoxic CsCuI is able to serve as a prospective candidate for stable solar-blind UV photodetection.
近年来，自供电型日盲紫外（UV）光电探测器因其在军事和民用领域的重要应用而受到全球关注。在本研究中，首次采用双源气相共沉积技术制备了无毒卤化铜CsCuI，并将其与β-GaO晶片集成，构建用于光电探测应用的II型异质结。通过优化退火条件，获得了具有致密形态、高结晶度和1.02 μs长载流子寿命的高质量CsCuI薄膜。由于CsCuI薄膜具有较高的材料完整性以及从CsCuI到β-GaO的有效界面载流子转移，异质结器件表现出良好的日盲紫外响应特性，且在零偏压下工作。通常，该光电探测器在零偏压下呈现出低暗电流（约1.2 pA）、高日盲/UVA抑制比（约1.0×10）、相对较快的光响应速度（37/45 ms）和高光暗电流比（约5.1×10）。此外，即使在环境空气中未封装连续工作12小时和储存2个月后，该器件的光电探测能力仍几乎能够保持，显示出出色的空气稳定性。我们的结果表明，无毒的CsCuI能够作为稳定日盲紫外光电探测的潜在候选材料。
