Anandan Manickam, Hsieh Ho-Feng, Liu Fang-Chen, Chen Chi-Yang, Lee Kuei-Yi, Chao Liang-Chiun, Ho Ching-Hwa, Chen Ruei-San
Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
Nanotechnology. 2020 Nov 13;31(46):465201. doi: 10.1088/1361-6528/abac7e.
Photoconductivities (PCs) with high responsivity in two-dimensional (2D) diindium triselenide (InSe) nanostructures with α-phase hexagonal structure were studied. The InSe nanosheet photodetectors fabricated by focused-ion beam technique exhibit broad spectral response with wavelength range from 300 nm to 1000 nm. The InSe nanosheets achieve optimal responsivity of 720 A W in near-infrared region (808 nm), and detectivity of 2.2 × 10 Jones, which were higher than several 2D material photodetectors. The physical origins that result in high photoresponse in InSe nanosheets such as carrier lifetime and mobility were also characterized by time-resolved PC and field-effect transistor measurements. The fast (hundred microseconds to milliseconds) and slow (seconds and longer) current rise or decay processes were both observed during the photoresponse. The narrowing (or relaxation) of depletion region and oxygen-sensitized photoconduction mechanism were suggested to be the causes of the efficient photoresponse in the InSe nanostructure detectors. All these observations suggest that α-InSe nanosheets could be a promising candidate for photosensitive material applications.
研究了具有α相六角结构的二维二铟三硒化物（InSe）纳米结构中具有高响应度的光电导率（PCs）。通过聚焦离子束技术制备的InSe纳米片光电探测器表现出从300nm到1000nm的宽光谱响应。InSe纳米片在近红外区域（808nm）实现了720 A/W的最佳响应度，以及2.2×10琼斯的探测率，高于几种二维材料光电探测器。还通过时间分辨PC和场效应晶体管测量对导致InSe纳米片中高光响应的物理起源，如载流子寿命和迁移率进行了表征。在光响应过程中观察到了快速（几百微秒到毫秒）和缓慢（秒及更长时间）的电流上升或衰减过程。耗尽区的变窄（或弛豫）和氧敏化光电导机制被认为是InSe纳米结构探测器中高效光响应的原因。所有这些观察结果表明，α-InSe纳米片可能是光敏材料应用的有前途的候选者。
