Guo Daoyou, Su Yuanli, Shi Haoze, Li Peigang, Zhao Nie, Ye Junhao, Wang Shunli, Liu Aiping, Chen Zhengwei, Li Chaorong, Tang Weihua
Center for Optoelectronics Materials and Devices & Key Laboratory of Optical Field Manipulation of Zhejiang Province, Department of Physics , Zhejiang Sci-Tech University , Hangzhou 310018 , China.
Laboratory of Information Functional Materials and Devices & State Key Laboratory of Information Photonics and Optical Communications, School of Science , Beijing University of Posts and Telecommunications , Beijing 100876 , China.
ACS Nano. 2018 Dec 26;12(12):12827-12835. doi: 10.1021/acsnano.8b07997. Epub 2018 Dec 3.
Ultraviolet (UV) radiation has a variety of impacts including the health of humans, the production of crops, and the lifetime of buildings. Based on the photovoltaic effect, self-powered UV photodetectors can measure and monitor UV radiation without any power consumption. However, the current low photoelectric performance of these detectors has hindered their practical use. In our study, a super-high-performance self-powered UV photodetector based on a GaN/Sn:GaO pn junction was generated by depositing a Sn-doped n-type GaO thin film onto a p-type GaN thick film. The responsivity at 254 nm reached up to 3.05 A/W without a power supply and had a high UV/visible rejection ratio of R/ R = 5.9 × 10 and an ideal detectivity at 1.69 × 10 cm·Hz·W, which is well beyond the level of previous self-powered UV photodetectors. Moreover, our device also has a low dark current (1.8 × 10A), a high I/ I ratio (∼10), and a fast photoresponse time of 18 ms without bias. These outstanding performance results are attributed to the rapid separation of photogenerated electron-hole pairs driven by a high built-in electric field in the interface depletion region of the GaN/Sn:GaO pn junction. Our results provide an improved and easy route to constructing high-performance self-powered UV photodetectors that can potentially replace traditional high-energy-consuming UV detection systems.
紫外线（UV）辐射具有多种影响，包括对人类健康、农作物产量以及建筑物寿命的影响。基于光伏效应，自供电紫外光电探测器可以在无需任何功耗的情况下测量和监测紫外线辐射。然而，目前这些探测器的低光电性能阻碍了它们的实际应用。在我们的研究中，通过在p型氮化镓（GaN）厚膜上沉积掺锡n型氧化镓（Sn:GaO）薄膜，制备了一种基于GaN/Sn:GaO pn结的超高性能自供电紫外光电探测器。在无电源的情况下，该探测器在254 nm处的响应度高达3.05 A/W，具有5.9×10的高紫外/可见光抑制比R/R，以及1.69×10 cm·Hz·W的理想探测率，这远远超过了以往自供电紫外光电探测器的水平。此外，我们的器件还具有低暗电流（1.8×10A）、高I/I比（~10）以及无偏压时18 ms的快速光响应时间。这些优异的性能结果归因于GaN/Sn:GaO pn结界面耗尽区中高内建电场驱动的光生电子 - 空穴对的快速分离。我们的研究结果为构建高性能自供电紫外光电探测器提供了一种改进且简便的途径，这种探测器有可能取代传统的高能耗紫外检测系统。
