Light-Modulated Subthreshold Swing Effect in a MoS2-Si Hetero Mosfet

A light-modulated subthreshold swing (SS) effect in a MoS2-Si hetero MOSFET is discovered. The device is essentially a SOI MOSFET with MOS2 top gate and partly gated channel. In the experiment, the SS of the device reduces from 100.2mV/dec to 70.4mV/dec under light illumination. In the TCAD simulation, the SS also shows similar light-modulated characteristic. The operation principle is mainly determined by the extra photovoltage at the top gate interface, as confirmed by the simulated results.