Wafer-Scale Fabrication of Sub-10 nm TiO(2)-Ga(2)O(3)n-p Heterojunctions with Efficient Photocatalytic Activity by Atomic Layer Deposition

ABSTRACT: Wafer-scale, conformal, two-dimensional (2D) TiO(2)-Ga(2)O(3) n-p heterostructures with a thickness of less than 10 nm were fabricated on the Si/SiO(2) substrates by the atomic layer deposition (ALD) technique for the first time with subsequent post-deposition annealing at a temperature of 250 °C. The best deposition parameters were established. The structure and morphology of 2D TiO(2)-Ga(2)O(3) n-p heterostructures were characterized by the scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), etc. 2D TiO(2)-Ga(2)O(3) n-p heterostructures demonstrated efficient photocatalytic activity towards methyl orange (MO) degradation at the UV light (λ = 254 nm) irradiation. The improvement of TiO(2)-Ga(2)O(3) n-p heterostructure capabilities is due to the development of the defects on Ga(2)O(3)-TiO(2) interface, which were able to trap electrons faster. GRAPHICAL ABSTRACT: [Image: see text]