The study on two different design and fabrication of visible light photodetection based on In2Se3-WS2 heterojunction

Since the discovery of graphene, extensive research has been conducted on two-dimensional (2D) materials with similar structures due to their exceptional photoelectric properties. Transition metal disulfide compounds (TMDCs) have emerged as promising candidates for photodetector applications owing to their remarkable physical characteristics. This study investigates the photoelectric properties of heterojunctions made of WS2 and In2Se3, which are 2D materials of significant interest. The heterojunctions are prepared using a dry transfer technique, and device electrodes are etched using the e-beam lithography (EBL) method. Through photoelectric performance testing, it is found that the carrier mobility of In2Se3/WS2 Field Effect Transistors (FET) is 6.89 square cm2/(V·s). The photoelectric properties of the devices are evaluated at three different wavelengths: 405 nm, 520 nm, and 638 nm. The corresponding optical responsivity values are measured as 6.35A/W, 2.39A/W, and 0.25A/W respectively while the optical response times are determined as 112.6 ms, 49.9 ms, and 71.8 ms for each wavelength respectively. The In2Se3/WS2 heterojunctions show a better performance than WS2/Si devices. This work reveals the potential application of In2Se3/WS2 heterojunctions in high-performance photodetection within the visible light range.