NUSOD Blog

Connecting Theory and Practice in Optoelectronics

Surface plasmon-enhanced photodetection in MoS2 phototransistors

weida+blog2Graphene and related 2-dimensional (2D) materials have emerged as potential building blocks for a variety of fundamental optical and electronic components, including field-effect transistors, nonvolatile memory devices, photonics devices, and phototransistors. Recently, molybdenum disulfide (MoS2) materializes as an alternative 2D nanoflake, due to its optical sensitivity, mechanical flexibility, extraordinary on/off ratio, absence of dangling bonds and compatibility to silicon CMOS processes, which may overcome the drawbacks of graphene. However, the performance of previously reported MoS2 phototransistors is limited by the low photoresponsivity which is largely due to its poor light absorption properties. Read more of this post

How to simulate the photogating effect in InAs nanowire phototransistors?

phototransistorSemiconductor nanowires promise light detection with enhanced sensitivity and faster transport speed. However, the short photocarrier lifetime, small light-sensing area, and weak optical absorption of nanowires cause serious problems. A possible solution lies in the photogating effect of semiconductor nanostructures, which was recently utilized in graphene-based phototransistors. Photocarriers located near the conductive channel form a strong local electric field to regulate the channel conductance through capacitive coupling. Read more of this post