Ultrathin 2D ternary Bi_(2)Te_(2)Se flakes for fast-response photodetectors with gate-tunable responsivity  

超薄二维三元Bi_(2)Te_(2)Se纳米片用于响应度栅压可调的快速响应光电探测器

作　　者：Peng Luo Ke Pei Fakun Wang Xin Feng Huiqiao Li Xitao Liu Junhua Luo Tianyou Zhai 罗鹏;裴颗;王发坤;冯昕;李会巧;刘希涛;罗军华;翟天佑(State Key Laboratory of Materials Processing and Die&Mould Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou 350002,China)

机构地区：[1]State Key Laboratory of Materials Processing and Die&Mould Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China [2]State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou 350002,China

出　　处：《Science China Materials》2021年第12期3017-3026,共10页中国科学（材料科学（英文版）

基　　金：supported by the National Natural Science Foundation of China (21825103);Hubei Provincial Natural Science Foundation of China (2019CFA002);the Fundamental Research Funds for the Central Universities (2019kfy XMBZ018)。

摘　　要：Two-dimensional(2D) ternary materials have sprung up in a broad variety of optoelectronic applications due to their robust degree of freedom to design the physical properties of the materials through adjusting the stoichiometric ratio. However, the controlled growth of high-quality 2D ternary materials with good chemical stoichiometry remains challenging, which severely impedes their further development and future device applications. Herein, we synthesize ternary Bi_(2)Te_(2)Se(BTS) flakes with a thickness down to 4 nm and a lateral dimension about 60 μm by an atmospheric-pressure solid source thermal evaporation method on a mica substrate. The phonon vibration and electrical transportation of 2D BTS are respectively investigated by temperature-dependent Raman spectrum and conductivity measurements. Furthermore, the photodetector based on 2D BTS exhibits excellent performance with a high light on/off ratio of 1300(365 nm), a wide spectral response range from 365 to 980 nm, and an ultra-fast response speed up to 2 μs. In addition, its electrical and photoelectric properties can be modulated by the gate voltage, offering an improved infrared responsivity to 2.74 A W^(-1) and an on/off ratio of 2266 under 980 nm. This work introduces an effective approach to obtain 2D BTS flakes and demonstrates their excellent prospects in optoelectronics.二维(2D)三元材料近年来如雨后春笋般兴起,由于其物理性质能够通过调整化学计量比来实现自由设计而被认为在光电子学中具有重要的应用前景.然而,具有良好化学计量比的高质量二维三元材料的可控制备仍然面临挑战,严重阻碍了它们进一步的发展和在未来器件中的应用.本文中,我们通过一种常压固体源热蒸发法在云母衬底上制备了厚度薄至4 nm,横向尺寸约为60μm的三元Bi_(2)Te_(2)Se(BTS)薄片.通过变温拉曼光谱和导电性测量研究了二维BTS的声子振动和电传输特性.进一步地,基于二维BTS的光电探测器表现出优异的光电响应特性,其光开关比在365 nm光照下约为1300,光谱响应范围宽至365–980 nm,同时其响应速度快至2μs.此外,栅极电压能够有效调控BTS的电输运和光电性能,从而将980 nm下的红外响应度和光开关比提高至2.74 A W^(-1)和2266.我们的工作介绍了一种有效获得二维BTS薄片的方法,并展示了其在光电领域良好的应用前景.

关 键 词：2D materials ternary materials Bi_(2)Te_(2)Se PHOTODETECTORS field-effect transistors 

分 类 号：TN15[电子电信—物理电子学] TB383.1[一般工业技术—材料科学与工程]