Wide band gap and conducting tungsten carbide (WC) thin films prepared by hot wire chemical vapor deposition (HW-CVD) method

Abstract

In this letter, we report synthesis of tungsten carbide (WC) thin films having wide band gap(3.22-3.3 eV) with high electrical conductivity (80-1260 S/cm) by HW-CVD using heated using heated W filament and Tetra-fluoro-methane (CF4) gas. Formation of WC was confirmed by low angle XRD, Raman spectroscopy and x-ray photoelectron spectroscopy. UV-Visible spectroscopy analysis revealed that the synthesized films have high transmission at wavelength 500 nm. Electrical properties measured using Hall measurement show that these films are semiconductor. The obtained results imply that the growth of WC thin films is mainly from the atomic species(W and C) evaporated from the hot filament. The HW-CVD opens a novel route to synthesize wide band gap and conducting WC at a cost-efficient way for DSSCs and hydrogen evolution reaction (HER)