MoS2-based transistor with asymmetric Schottky contacts for self-powered broadband photodetection and visual synapse

Abstract

The Schottky interface in metal–semiconductor contacts significantly affects and even dominates the performance of semiconductor devices. Therefore, accurately characterizing and regulating the Schottky barrier at the interface is of great research significance. In this report, the Au/MoS2/Ag transistor is fabricated by using an asymmetric electrode configuration. Under 405 nm light illumination, a maximum photocurrent density of 7.7 mA/cm2 is observed, and the on/off ratio reaches 6.31 × 104. For incident light wavelengths of 660, 808, 1064, and 1550 nm, the measured maximum photocurrent density values are 2.44, 0.044, 0.015, and 5.6 × 10−4 mA/cm2, respectively. Moreover, under bias voltage, the transistor exhibits dynamic properties similar to the visual synapses including paired-pulse facilitation, short-term plasticity, and long-term plasticity by light pulses. Under the 405 nm light irradiation, the power consumption per spike and the energy consumption are as low as 0.31 pW and 7.22 pJ, respectively. Evidently, the Au/MoS2/Ag transistor possesses significant development potential and presents promising prospects in broadband detection and low power artificial visual systems.