Self‐Powered MoS 2 –PDPP3T Heterotransistor‐Based Broadband Photodetectors

Photodetectors based on monolayer molybdenum disulfide (MoS 2 ) have been demonstrated to exhibit good photodetecting capabilities. However, the relatively large bandgap of monolayer MoS 2 has inhibited its application in near‐infrared (NIR) photodetectors. Here, the narrow‐bandgap organic semiconductor poly(diketopyrrolopyrrole‐terthiophene) (PDPP3T) is firstly introduced to the monolayer MoS 2 transistor as a NIR light absorbing layer. The MoS 2 –PDPP3T heterojunction‐based transistor (heterotransistor) shows a broadband photodetecting range from ultraviolet (UV) to NIR region. About one or two orders of magnitude improvement of photoresponsivities have been realized for the MoS 2 –PDPP3T heterotransistor compared with that of MoS 2 transistor. Moreover, due to the formation of MoS 2 –PDPP3T heterojunction and asymmetric electrodes, the MoS 2 –PDPP3T heterotransistor shows the self‐powered behavior under zero bias voltage. Flexible MoS 2 –PDPP3T heterostructure photodetector is also fabricated on the poly(ethylene terephthalate) substrate with reliable performance, which enables a promising photodetection platform for future wearable optoelectronics.