MoS₂ nanosheet photodetectors with ultrafast response

Two-dimensional layered materials, such as molybdenum disulfide, are emerging as an exciting material system for future electronics due to their unique electronic properties and atomically thin geometry. In this work, MoS₂-based FETs are fabricated using mechanical cleavage and standard photolithographic and metal evaporation techniques, and the detector exhibits a good ohmic contact. We show that the multilayer molybdenum disulfide photodetector has a fast photoresponse as short as 42 μs. The fast photodetector response is due to the decrease in the trap states in MoS₂ flakes compared to monolayer MoS₂, making its photoresponse time close to its intrinsic response. The large photocurrent with the responsivity and external quantum efficiency of 59 A/W and 13 800% for the wavelength of 532 nm was also measured. The fast response time, high responsivity, and the ease of fabrication of these devices make them important components for future optoelectronic devices.