Photosensitive Schottky barrier diodes based on Cu/p-SnSe thin films fabricated by thermal evaporation

Abstract

Tin selenide (SnSe), a group IV–VI compound semiconductor material, is used to fabricate various solid-state devices such as memory switching devices, P–N junction diodes, Schottky barrier diodes, etc. In the present study, a Cu/p-SnSe Schottky junction was fabricated by a thermal evaporation technique. SnSe charge was grown using the DVT method, and subsequently its film was deposited using a thermal evaporation process. Energy dispersive X-ray analysis (EDAX) confirmed the stoichiometry of the elements in the as deposited thin film. X-ray diffraction (XRD) was used to identify its structure, which revealed an orthorhombic structure. Raman spectroscopy revealed vibrational modes, whereas UV-Vis spectroscopy revealed an optical band gap of 1.75 eV. Structural information was obtained using AFM, SEM, HR-TEM, and SAED. A Cu thin film was deposited on top of the SnSe thin film, and a Schottky device was fabricated. The Schottky device parameters were determined based on the current–voltage (I–V) characteristics. We observed that, under illumination conditions, the device performance improves, which indicates that the fabricated diode exhibits an adequate photosensitive nature.