Constructing Conductive MoOx Thin Films by Plasma-Enhanced Atomic Layer Deposition

Herein, amorphous molybdenum oxide films are constructed by thermal atomic layer deposition (T-ALD) and plasma-enhanced atomic layer deposition (PE-ALD). The physical and chemical properties of molybdenum oxide films prepared by the two methods are systematically compared by means of film growth law, atomic force microscope, scanning electron microscope, etc. The results show that the amorphous molybdenum oxide physical phase prepared by both ALD methods is MoO 3 . Compared with T-ALD MoO 3 , the growth rate of MoO 3 thin films prepared by PE-ALD is higher. Compared to PE-ALD MoO 3 , the MoO 3 films prepared by T-ALD did not have nucleation delayed to a laminar growth mode, resulting in smoother deposited films and contained less impurity carbon. The MoO 3 prepared by PE-ALD contains 7.4% impurity carbon. This carbon-doped film significantly improves the conductivity of the MoO 3 film and shows good electrochemical activity. As expected, the MoO 3 films prepared by PE-ALD show good electrocatalytic oxygen evolution reaction. The overpotential is only 259 mV at 10 mA cm −2 and continues to evolution oxygen for 60 h with almost no attenuation, indicating that carbon doping significantly improves the catalytic intrinsic activity and stability of MoO 3 .