摘要
Solar-blind ultraviolet photodetectors with metal-semiconductor-metal structure were fabricated based onβ-(Al_(0.25)Ga_(0.75))_(2)O_(3)/β-Ga_(2)O_(3) film grown by metal-organic chemical vapor deposition.It was known that various surface states increase dark current and a large number of defects can hinder the transport of carriers,resulting in low switching ratio and low responsivity of the device.In this work,β-(Al_(0.25)Ga_(0.75))_(2)O_(3) films are used as surface passivation materials.Owning to its wide band gap,we obtain excellent light transmission and high lattice matching withβ-Ga_(2)O_(3).We explore the change and mechanism of the detection performance of theβ-Ga_(2)O_(3) detector afterβ-(Al_(0.25)Ga_(0.75))_(2)O_(3) surface passivation.It is found that under the illumination with 254 nm light at bias 5 V,theβ-(Al_(0.25)Ga_(0.75))_(2)O_(3)/β-Ga_(2)O_(3)photodetectors show dark current of just 18 pA and high current on/off ratio of 2.16×10^(5).The dark current is sharply reduced about 50 times after passivation of theβ-Ga_(2)O_(3) surface,and current on/off ratio increases by approximately 2 times.It is obvious thatβ-Ga_(2)O_(3) detectors withβ-(Al_(0.25)Ga_(0.75))_(2)O_(3) surface passivation can offer superior detector performance.
作者
岳建英
季学强
李山
岐晓辉
李培刚
吴真平
唐为华
Jian-Ying Yue;Xue-Qiang Ji;Shan Li;Xiao-Hui Qi;Pei-Gang Li;Zhen-Ping Wu;Wei-Hua Tang(Laboratory of Optoelectronics Materials and Devices,School of Science,Beijing University of Posts and Telecommunications,Beijing 100876,China;State Key Laboratory of Information Photonics and Optical Communications,Beijing University of Posts and Telecommunications,Beijing 100876,China;College of Electronic and Optical Engineering&College of Microelectronics,National and Local Joint Engineering Laboratory for RF Integration and Micro-Packaging Technologies,Nanjing University of Posts and Telecommunications,Nanjing 210046,China)
基金
Project supported by China Postdoctoral Science Foundation (Grant No.042600055)
Research on Frontiers of Materials Science,Beijing Municipal Science and Technology Commission (Grant No.Z181100004418006)。
