MoS2/pentacene hybrid complementary inverter based photodetector with amplified voltage–output

Abstract

A sensitive photodetection based on a novel hybrid CMOS inverter has been demonstrated. Unlike common photo-current type photodetectors, which convert optical signals to current, the CMOS inverter realizes voltage–output, overcoming the difficulty to monitor current signal in the range of nA. The hybrid CMOS logic inverter employs n-channel MoS2 nanosheet/perovskite heterojunction FET and p-channel organic pentacene FET in a planar architecture. In order to obtain high performance, we adopt the interdigital electrodes for the pentacene FET to enhance the current density of the p-channel, and stack perovskite on the MoS2 channel to modify the threshold voltage of the n-channel. As a result, a CMOS inverter with a voltage gain of more than ten is obtained. When VIN is around the transition voltage (−38 V), the inverter can obtain stable optical detection signal, the VOUT changes from 6 V in dark to 1 V under 633 nm light exposure. This finding indicates the potential to fabricate visible light detecting devices with voltage–output based on the inverter and may be further applicable for a photo-logic circuit.