Electrically Modulated Single/Multicolor High Responsivity 2D MoTe2/MoS2 Photodetector for Broadband Detection

A multicolor imaging system can enhance the detection and identification distance of a target object by comparing images measured with distinguishable wavelength bands. To achieve high performance of multicolor detection, high responsivity within ultra-broadband is essentially required for increasing the resolution of the photodetector. In this study, we developed single/multicolor detection with high responsivity within ultra-broadband by a two-dimensional van der Waals MoTe2/MoS2 heterostructure. Owing to interlayer transition at the type-II staggered heterojunction, the proposed device can perform photodetection from visible-to-infrared wavelengths (400–1480 nm) exhibiting high responsivities of 9.74, 2.65, and 0.416 A/W under illumination at wavelengths of 520, 980, and 1310 nm, respectively, with a fast photoresponse time of 42 μs, under reverse bias voltage. At 802 nm (visible region), 1143 nm (NIR region), and 1485 nm (IR region), three unique cutoff wavelengths clearly appeared, and multicolor imaging at room temperature was possible by matching images measured with three different wavelength bands. The multicolor image could be converted to a single-color image without the use of optical filters by applying a forward bias voltage. Our proposed MoTe2/MoS2 heterostructure enabling electrically modulated single/multicolor imaging can contribute to the practical applications of high-resolution photodetectors.