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

Abstract

A multicolor imaging system can enhance the detectionand identificationdistance of a target object by comparing images measured with distinguishablewavelength bands. To achieve high performance of multicolor detection,high responsivity within ultra-broadband is essentially required forincreasing the resolution of the photodetector. In this study, wedeveloped single/multicolor detection with high responsivity withinultra-broadband by a two-dimensional van der Waals MoTe2/MoS2 heterostructure. Owing to interlayer transitionat the type-II staggered heterojunction, the proposed device can performphotodetection from visible-to-infrared wavelengths (400-1480nm) exhibiting high responsivities of 9.74, 2.65, and 0.416 A/W underillumination at wavelengths of 520, 980, and 1310 nm, respectively,with a fast photoresponse time of 42 & mu;s, under reverse biasvoltage. At 802 nm (visible region), 1143 nm (NIR region), and 1485nm (IR region), three unique cutoff wavelengths clearly appeared,and multicolor imaging at room temperature was possible by matchingimages measured with three different wavelength bands. The multicolorimage could be converted to a single-color image without the use ofoptical filters by applying a forward bias voltage. Our proposed MoTe2/MoS2 heterostructure enabling electrically modulatedsingle/multicolor imaging can contribute to the practical applicationsof high-resolution photodetectors.