Room temperature deposition of highly conductive and transparent hydrogen and tungsten co-doped ZnO films for thin film solar cells applications

Highly conductive and transparent hydrogen and tungsten co-doped ZnO (HWZO) films were prepared at room temperature using a pulsed magnetron sputtering method. The influences of H2/Ar ratio on the structural, electrical, and optical properties of HWZO films were investigated. The enhancements of the crystallinity and improvement of electrical and optical properties of HWZO thin films were achieved for hydrogen incorporation. The minimum resistivity of 8.33×10−4 Ω cm with mobility of 40.8 cm2/V· s and carrier concentration of 1.84×1020 cm−3 was achieved at the optimized H2/Ar doping ratio of 7.84%. The high transmittance extends from the visible region into the near-infrared region with an average transmittance of 80% at the wavelength region from 380 nm to 1800 nm. The experimental results demonstrate that the pulsed magnetron sputtering is a viable method for cost effective fabrication of low resistivity and high transmittance HWZO films.