Mechanical transfer electrode can effectively reduce the contact surface between the electrode and semiconductor material, however this method has not been applied to improve the performance of photoelectric devices. In this paper, MoS2 thin film photodetectors are fabricated by this novel method. Compared with the MoS2 thin film photodetectors prepared by the traditional hot evaporation method, the dark current of the transfer device decreased by nearly one order of magnitude, reaching 4.6 × 10-7 A, and the detectivity also increased significantly to 2.1 × 1010 Jones. All these results show that the mechanical transfer electrode can optimize the contact interface between the electrode and semiconductor material to achieve a higher performance photodetector.
GaAs nanowires have widely applied in infrared devices in the past few years. However, the performance of GaAs nanowire photodetectors is strongly limited by the problem of large surface state density. At the same time, onedimensional GaAs nanowire as photosensors for infrared detection has been seldom studied. In this paper, a single GaAs nanowire infrared photodetector have been successfully fabricated and Ar plasma treatment is performed on the device to improve the performance. The treated GaAs nanowire device exhibits high responsivity of 108 A/W, which is about 6 times larger than the original one (~18 A/W). Besides, the external quantum efficiency up to 25312 % and the detectivity up to 9.21×1011 cmHz0.5W-1. At the same time, the response time τr is significantly reduces from 86.40 ms to 3.36 ms, and the recovery time τf is almost remained as 212.48 ms. The significant enhancement is due to the improvement of nanowires surface quality. These results demonstrate that GaAs nanowire is an outstanding material in infrared field devices and plasma treatment is an effective way to realize high performance nanowire photodetectors.