Two-Dimensional MoS₂-Based Photosensitive Al/MoS₂/SiO₂/Si/Ag MOS Capacitor

Abstract

This paper reports the seamless fabrication of an Al/MoS ₂ /SiO ₂ /Si/Ag structure metal-oxide-semiconductor (MOS) photosensitive capacitor using two-dimensional (2D) MoS ₂ films. The ~2 nm MoO ₃ thin film is transformed into a 2D MoS ₂ film through sulfurization in the vapor phase reaction. The morphological, structural and photophysical properties of the transformed MoS ₂ films are investigated using Raman spectroscopy, atomic force microscopy, energy-dispersive X-ray spectroscopy, UV-Vis spectroscopy, and X-ray photoelectron spectroscopy. It is found that the grown MoS ₂ films are of good quality and continuous over the entire surface. The fabricated MoS ₂ based MOS capacitor is electrically characterized through aluminum and silver contacts. When the MOS capacitor is exposed to light, its capacitance is observed to be increasing with the light intensity. The unbiased capacitance of 477 pF under dark condition is increased to 591 pF when exposed with light (λ ~ 600 nm) of 500 μW/cm ² .