Phototransistors with Negative or Ambipolar Photoresponse Based on As‐Grown Heterostructures of Single‐Walled Carbon Nanotube and MoS2

Abstract A facile synthesis method for the heterostructures of single‐walled carbon nanotubes (SWCNTs) and few‐layer MoS 2 is reported. The heterostructures are realized by in situ chemical vapor deposition of MoS 2 on individual SWCNTs. Field effect transistors based on the heterostructures display different transfer characteristics depending on the formation of MoS 2 conduction channels along SWCNTs. Under light illumination, negative photoresponse originating from charge transfer from MoS 2 to SWCNT is observed while positive photoresponse is observed in MoS 2 conduction channels, leading to ambipolar photoresponse in devices with both SWCNT and MoS 2 channels. The heterostructure phototransistor, for negative photoresponse, exhibits high responsivity (100–1000 AW −1 ) at low bias voltages (0.1 V) in the visible spectrum (500–700 nm) by combining high mobility conduction channel (SWCNT) with efficient light absorber (MoS 2 ).