Wang Yifan, Zhu Yu, Gu Huaimin, Wang Xingfu
School of Semiconductor Science and Technology, South China Normal University, Guangzhou 510631, China.
ACS Appl Mater Interfaces. 2021 Dec 8;13(48):57750-57758. doi: 10.1021/acsami.1c14319. Epub 2021 Nov 23.
Although pyroelectric photodetectors have been intensively studied, the transient temperature change rate of pyroelectric materials is a main restrictive factor for improving the performance. In this work, we fabricate an ultrafast response self-powered near-infrared (NIR) photodetector (PD) based on Au nanoparticles (NPs) coated an n-ZnO nanowires (NWs)/p-Si heterojunction. The local surface plasmon resonance (LSPR) effect generated at the local contacts of Au NPs/ZnO NWs can significantly enhance the transient temperature change rate of the ZnO material to improve the photoresponse performances of the NIR PD. Compared with that in the pristine ZnO-based PD, the response time of the Au-coated NIR PD is decreased from 113 to 50 μs at the rising edge and 200 to 70 μs at the falling edge. Optical responsivity and detectivity of the Au-coated ZnO-based PD are increased by 212 and 266%, respectively. The pyroelectric current gain is produced by injecting hot electrons from the LSPR effect of Au NPs into the ZnO material and the thermal energy transfer caused by the photothermal effect of plasmonic Au nanostructure. This work provides an in-depth understanding of plasmonic effect-enhanced pyroelectric effect and presents a unique strategy for developing high-performance NIR photodetectors.
尽管热释电光电探测器已得到深入研究，但热释电材料的瞬态温度变化率是提高其性能的主要限制因素。在这项工作中，我们基于涂覆有金纳米颗粒（NPs）的n-ZnO纳米线（NWs）/p-Si异质结制备了一种超快响应自供电近红外（NIR）光电探测器（PD）。在Au NPs/ZnO NWs的局部接触处产生的局域表面等离子体共振（LSPR）效应可以显著提高ZnO材料的瞬态温度变化率，从而改善NIR PD的光响应性能。与原始的基于ZnO的PD相比，涂金的NIR PD在上升沿的响应时间从113 μs降至50 μs，在下降沿从200 μs降至70 μs。涂金的基于ZnO的PD的光学响应度和探测率分别提高了212%和266%。热释电电流增益是通过将来自Au NPs的LSPR效应的热电子注入到ZnO材料中以及由等离子体Au纳米结构的光热效应引起的热能转移而产生的。这项工作深入理解了等离子体效应增强的热释电效应，并为开发高性能NIR光电探测器提出了一种独特的策略。
