MoS2 Phototransistors Photogated with a P-N Junction Diode

Abstract

Photodetectors based on two-dimensional (2D) atomically thin semiconductors suffer from low light absorption, limiting their potential for practical applications. In this work, we demonstrate high-performance MoS2 phototransistors by integrating few-layer MoS2 on a PN junction formed on a silicon (Si) substrate. The photovoltage created in the PN junction under light illumination electrically gates the MoS2 channel, creating a strong photoresponse in MoS2. We present a theory to predict the photocurrent of the proposed phototransistor architecture as a function of light intensity, wavelength, and temperature. Our derived formulas for photocurrent and responsivity under varying conditions ali..