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.