Comparative study of photocarrier dynamics in CVD-deposited CuWO${}_4$, CuO, and WO${}_3$ thin films for photoelectrocatalysis

The temporal evolution of photogenerated carriers in CuWO${}_4$, CuO and WO${}_3$ thin films deposited via a direct chemical vapor deposition approach was studied using time-resolved microwave conductivity and terahertz spectroscopy to obtain the photocarrier lifetime, mobility and diffusion length. The carrier transport properties of the films prepared by varying the copper-to-tungsten stoichiometry were compared and the results related to the performance of the compositions built into respective photoelectrochemical cells. Superior carrier mobility was observed for CuWO${}_4$ under frontside illumination.