Ultrasensitive and high-speed AlGaN/AlN solarblind ultraviolet photodetector:a full-channelself-depleted phototransistor by a virtual photogate  

作　　者：JIABING LU ZESHENG LV XINJIA QIU SHIQUAN LAI HAO JIANG 

机构地区：[1]School of Electronics and Information Technology,Sun Yat-sen University,Guangzhou 510006 China [2]State Key Laboratory of Optoelectronic Materials and Technologies,Sun Yat-sen University,Guangzhou 51006 China [3]Guangdong Engineering Technology R&D Center of Compound Semiconductors and Devices,Sun Yat-sen University,Guangzhou 510006,China

出　　处：《Photonics Research》2022年第9期2229-2238,共10页光子学研究（英文版）

基　　金：Key Realm R&D Program of Guangdong Province(2019B010132004,2020B010172001);Key Realm R&D Program of Guangzhou(202103030002)。

摘　　要：High sensitivity,high solar rejection ratio,and fast response are essential characteristics for most practical applications of solar-blind ultraviolet(UV)detectors.These features,however,usually require a complex device structure,complicated process,and high operating voltage.Herein,a simply structured n-Al Ga N/Al N phototransistor with a self-depleted full channel is reported.The self-depletion of the highly conductive n-Al Ga N channel is achieved by exploiting the strong polarization-induced electric field therein to act as a virtual photogate.The resulting two-terminal detectors with interdigital Ohmic electrodes exhibit an ultrahigh gain of 1.3×10^(5),an ultrafast response speed with rise/decay times of 537.5 ps/3.1μs,and an ultrahigh Johnson and shot noise(flicker noise)limited specific detectivity of 1.5×10^(18)(4.7×10^(16))Jones at 20-V bias.Also,a very low dark current of the order of~p A and a photo-to-dark current ratio of above 10^(8)are obtained,due to the complete depletion of the n-Al_(0.5)Ga_(0.5)N channel layer and the high optical gain.The proposed planar phototransistor combines fabrication simplicity and performance advantages,and thus is promising in a variety of UV detection applications.

关 键 词：TRANSISTOR channel POLARIZATION 

分 类 号：TN23[电子电信—物理电子学] TN32