光子学报 ›› 2019, Vol. 48 ›› Issue (12): 1248004-1248004.doi: 10.3788/gzxb20194812.1248004

• “瞬态光子学”专题 • 上一篇    下一篇

石墨烯/硅光电探测器的I-VC-V特性

方昕宇, 陈俊   

  1. 苏州大学 电子信息学院, 江苏 苏州 215006
  • 收稿日期:2019-06-24 发布日期:2019-12-30
  • 通讯作者: 陈俊(1981-),男,副教授,博士,主要研究方向为光电器件.Email:junchen@suda.edu.cn
  • 作者简介:方昕宇(1995-),男,硕士研究生,主要研究方向为石墨烯/硅光电探测器.Email:1120299167@qq.com
  • 基金资助:
    国家自然科学基金(No.61774108)

I-V and C-V Characteristics of Graphene/Silicon Photodetector

FANG Xin-yu, CHEN Jun   

  1. School of Electronic and Information Engineering, Soochow University, Suzhou, Jiangsu 215006, China
  • Received:2019-06-24 Published:2019-12-30
  • Supported by:
    The National Natural Science Foundation of China (No.61774108)

摘要: 设计并制备了基于石墨烯/n型硅肖特基结的光电探测器,并从能带角度研究和分析了其I-VC-V特性.结果表明,石墨烯/氮化硅/硅(金属-绝缘层-半导体)电容器对器件的I-VC-V特性有较大影响.在808 nm近红外光的照射下,器件反向电流和正向电流大小接近,归因于氮化硅/硅界面堆积的光生空穴向石墨烯/硅肖特基结的扩散,器件光响应度为0.26 A/W.基于热发射模型从I-V暗电流曲线提取的肖特基势垒高度及理想因子分别为0.859 eV和2.3.利用肖特基二极管耗尽层电容公式从C-2-V曲线提取的势垒高度随着频率的增加而增加并趋于稳定在0.82 eV.由于界面态的影响,石墨烯/硅肖特基结耗尽层宽度随频率增加而增加,而硅施主原子的掺杂浓度及器件电容则随频率增加而减小.

关键词: 石墨烯, 光电探测器, 能带分析, MIS电容器, 肖特基势垒高度, 界面态

Abstract: A photodetector based on Graphene/n-type Si Schottky junction is designed and fabricated. I-V and C-V characteristics are analyzed from the band energy perspective. The results show that Graphene/SiNx/Si(metal/insulation layer/semiconductor) capacitor has effects on device characteristics. Under the illumination of near-infrared light(808 nm), the photodetector exhibits that the reverse photocurrent is approximately the same value as the forward one owing to photo-generated holes, which diffuse from Si/SiNx interface to Graphene/Si junction and the responsivity is 0.26 A/W. The Schottky barrier height and ideality factor extracting from I-V dark current curve are 0.859 eV and 2.3 respectively based on thermionic emission model. The Schottky barrier height extracting from C-2-V curves on account of the equation of depletion layer capacitance increases and tends to be stable around 0.82 eV with increasing frequency. The value of depletion layer width of Gr/Si Schottky junction increases with increasing frequency, while doping concentration of Si donor atoms and capacitance of device decrease, which are attributed to surface states.

Key words: Graphene, Photodetector, Energy band analysis, MIS capacitor, Schottky barrier height, Surface states

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