Investigation of RF sputtered, n-Bi₂Se₃ heterojunction on p-Si for enhanced NIR optoelectronic applications

A significant deal of interest has been generated in heterojunctions made of 2D Bi-Chalcogenides and semiconducting materials due to the wide range of unique properties and functionalities that they exhibit. In this work RF magnetron sputtering technique was used to fabricate the high-quality n-Bi₂Se₃/p-Si heterojunction device. The structural properties of the grown Bi₂Se₃ thin films were examined by XRD, SEM, Raman and Energy dispersive spectroscopy. The current-voltage (I–V) characteristic revealed the development of effective p-n junction with a greatest rectification ratio (RR) of 724 and significant figure of merit (FOM) of 1.11. A visible to near-infrared photodetector was successfully constructed using n-Bi₂Se₃/p-Si heterostructure exhibiting a strong response to 1100 nm irradiance and demonstrated outstanding photo-responsivity of 43.3 A/W, an excellent detectivity of 2.08 × 10¹² Jones and convincing photoconductive gain of 48.71. The fabricated n-Bi₂Se₃/p-Si heterojunction offers inexpensive optical detection, high performance broadband detector and tremendous potential for superior electrical and optoelectronic applications due to its convenient device fabrication and compatibility with silicon technology.