Wafer-Scale Fabrication of Sub-10 nm TiO2-Ga2O3 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

Inherently Selective Atomic Layer Deposition and Applications

“…Atomic layer deposition (ALD) stands out as an ideal technique for farbicating films layer-by-layer with accurate thickness control, excellent uniformity and conformality. − Selective ALD takes the method to the next step, with the capability of controlling where to grow, while leaving adjacent areas intact . The surface sensitivity of selective ALD also makes it particularly appealing beyond the semiconductor industry to many emerging applications. − …”

Nanoscale Au-ZnO Heterostructure Developed by Atomic Layer Deposition Towards Amperometric H2O2 Detection

“…The development of different nanoscale two-dimensional (2D) heterostructures for their usage in various electrochemical devices is modern and established trend during the last decade of the twenty-first century [1][2][3][4][5]. So far, several technologies have been dominated in this trend including RF sputtering, chemical vapor deposition (CVD), hydrothermal method, solvothermal method, thermal evaporation, sol-gel, mechanical exfoliation, etc.…”

Phase junction enhanced photocatalytic activity of Ga2O3 nanorod arrays on flexible glass fiber fabric

“…41 Xu et al fabricated twodimensional TiO 2 -Ga 2 O 3 p-n heterostructures, demonstrating the contribution of heterostructures in enhancing photocatalytic activity. 45 Furthermore, the construction of appropriate phase junction structure in Ga 2 O 3 can also signicantly enhance photocatalytic activity. [46][47][48] Liu et al demonstrated that the mesopores and heterojunction in the mixed-phase Ga 2 O 3 are responsible for enhancing photocatalytic activity.…”