Top and back gate molybdenum disulfide transistors coupled for logic and photo-inverter operation

Abstract

We demonstrate an inverter type nanodevice based on 2-dimensional semiconducting molybdenum disulfide (MoS₂) nanoflakes. The inverter device was comprised of back-gate and top-gate field-effect transistors (FETs) which work respectively as a load and a driver for a logic inverter in the dark but switch their roles for photo-inverter operation. Our logic inverter shows a relatively high voltage gain of more than 12. When the back-gate FET controls the circuit as a driver to sensitively detect visible light using its open channel, the device effectively operates as a photo-inverter detecting visible photons. Our inverter based on top- and back-gate MoS₂ FETs would be quite promising for both logic and photo-sensing applications due to its performance and simple device configuration as well.