(Invited) Self-Powered Image Sensors Based on Vertical Van Der Waals 2H/1T' -MoTe2 Homojunctions

Abstract

Image sensors can convert optical images into electrical images, which play important roles in industrial application fields and emerging applications, including digital cameras, biomedical imaging, and machine visions. [1, 2] Compared to traditional three-dimensional rigid materials, two-dimensional (2D) materials with excellent electrical, optoelectrical, and mechanical properties exhibit great potentials in novel image sensors. This work aims to synthesize large scale van der Waals 1T’/2H MoTe2 homojunctions and fabricate image sensors for self-powered imaging functions. Firstly, a two-step chemical vapor deposition (CVD) method is adopted to synthesize the 1T’/2H MoTe2 homojunctions via tellurization process of molybdenum film. Secondly, the structural design of the self-powered photodetector based on 2H MoTe2 with asymmetric electrodes and the corresponding optoelectrical properties are investigated. [3] Thirdly, an image sensor consisting of a self-powered MoTe2 photodetectors array is constructed and exhibits excellent imaging functions with zero power electrical consumption. This work will open a new route to build image systems based on 2D materials, showing great opportunities in digital image systems with ultralow power consumption and excellent imaging functions. Acknowledgement This work was fully supported by a grant from the National Natural Science Foundation of China (Project No. 52022003).