Photoelectrochemical properties of MoO2 thin films

Thin MoO2 films were electrodeposited on a selenium pre-deposited SnO2|glass plate. The photoelectrochemical properties of MoO2 films were investigated in 0.1 M Na2SO4 solution by the ultraviolet-visible spectrophotometry, linear sweep voltammetry, and altering current impedance measurement techniques. It was found that under illumination with the incident light of lambda = 366 nm, the photo response of the MoO2|SnO2|glass electrode resulted from the MoO2 layer, while the SnO2 layer served as a sink for photogenerated charge carriers. The MoO2 film exhibited n-type conductivity. A schematic band structure diagram of MoO2 in 0.1 M Na2SO4 solution was constructed. The flat band potential (E (fb)), the donor concentration (N (D)), the photogeneration current efficiency depended on MoO2 film thickness. The [Fe(CN)(6)](4-/3-) redox PEC cell with MoO2|SnO2|glass plate as a photoanode was constructed. Power output characteristics such as the open circuit voltage (V (OC)), short circuit current (I (SC)), the fill factor (FF), and the light-to-electrical conversion efficiency (eta) were determined. The maximum light-to-electrical conversion efficiency exhibited by the PEC cell was 0.94 %.