Temperature dependent current- and capacitance-voltage characteristics of W/n-Si structures with two-dimensional WS2 and three-dimensional WO3 interfaces deposited by RF sputtering technique

In this study, tungsten disulfide (WS2) and tungsten trioxide (WO3) thin films are deposited on n-Si by RF sputtering technique. The optical, morphological and structural characteristics of these films are investigated. The XRD patterns showed that highly crystallinity have been obtained with dominant characteristic diffraction peaks of the WS2 and WO3. The SEM images show that these films are nearly uniform and covered all surface of substrates. Furthermore, the WS2 film has two-dimensional (2D) vertical layers while the WO3 has three-dimensional (3D) structure. From the XPS spectra, it revealed that the peaks confirmed the formation of WS2 and WO3 phases. The Raman spectra presented that different vibrational modes and phases are characteristics of the WS2 and WO3 thin films. Electrical properties of W/n-Si metal-semiconductor (MS) and W/WS2/n-Si and W/WO3/n-Si metal-interfacial layer-semiconductor (MIS) diodes are investigated using current-voltage (I-V) and capacitance-voltage (C-V) characteristics at various temperatures. It was found that I-V and C-V characteristics are strongly dependent on temperature and the interfacial WS2 and WO3 layers are significant roles for the electrical properties of W/WS2/n-Si and W/WO3/n-Si devices.