石墨烯MIS结宽光谱光电特性的研究

Study on Broad Spectrum Photoelectric Properties of Graphene MIS Junction

Ge基光电探测器具有独特的通信带宽响应特性和良好的CMOS工艺兼容性,在光电探测方面具有广阔的应用前景。但目前商用探测器的响应波段普遍局限在某一波段,难以满足多波段融合、小型化的探测需求。因此,通过在多层石墨烯和N型Ge之间引入薄的SiO_(2)界面层,制备了基于石墨烯金属-绝缘层-半导体(MIS)结的光电探测器,分析了SiO_(2)的厚度以及石墨烯层数对MIS结器件性能的影响,并测试了器件的光谱响应范围、电流-电压曲线、响应度、开关比等光电特性。结果表明,该器件在254~2200 nm波段内均有响应,在980 nm处的响应度和开关比达到峰值,分别为78.36 mA/W和1.74×10^(3),上升时间和下降时间分别为1 ms和3 ms。

The Gebased photodetector has a broad application prospect in light detection with its unique communication bandwidth response characteristics and good compatibility with CMOS technology.However,the response band of current commercial detectors is generally limited to a specific band,which is not easy to meet the detection requirements of multiband fusion and miniaturization.Therefore,in this paper,a graphene metalinsulator semiconductor(MIS)junctionbased photodetector is fabricated by introducing a thin SiO_(2) interface layer between multilayer graphene and Ntype Ge.The effect of SiO_(2) with different thicknesses and graphene layers in the MIS junction device is investigated.The influence of the number of layers on performance of the MIS junction device is also tested.The spectral response range,currentvoltage curve,responsivity,onoff ratio,and other optoelectronic properties of the device are tested.The results show that the device has a response in the wavelength range of 254-2200 nm,and the responsivity and the onoff ratio peaked at 980 nm,which are 73.86 mA/W and 1.74×10^(3),respectively.The rise and fall times are 1 ms and 3 ms,respectively.