Comparative investigations of DCMS/HiPIMS reactively sputtered WO3 thin films for photo-electrochemical efficiency enhancements

Abstract

Abstract In this work, different sets of WO3 thin films were separately deposited and compared based on reactive direct current magnetron sputtering (DCMS), and reactive high-power impulse magnetron sputtering (HiPIMS) techniques. Both sets of as-deposited WO3 thin films also underwent a thermal annealing treatment at 400 °C for 2 h in an air ambience for thorough investigations. After annealed treatments, the HiPIMS technique as observed from XRD and Raman spectroscopy showed well-pronounced WO3 film structures, and those as observed from the ellipsometry confirmed the increased film density based on high refractive index. The WO3 thin film prepared by the HiPIMS technique was found to have a higher photocurrent from water oxidation, and more stability than the prepared by DCMS technique due to the preferred crystalline structure with exposed highly active (002) facets. This work provides the potential of HiPIMS deposition technique to deposited semiconductor film for energy and environmental applications as well.