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-V及C-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-V及C-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.

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/SiN_x/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/SiN_x 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.