Comparative study of photoinduced wettability and photocatalytic activity in different crystalline Ga2O3 phases

The photoinduced wettability and photocatalytic activity of single -crystalline beta-Ga2O3 (s-Ga2O3), poly -crystalline beta-Ga2O3 (p-Ga2O3), and amorphous Ga2O3 (a-Ga2O3) are investigated under ultraviolet C irradiation, and their results are compared. beta-Ga2O3 has gained attention in photocatalytic applications due to its excellent thermodynamic stability and indirect bandgap properties. The s-Ga2O3 shows the highest efficiency in terms of both photoinduced hydrophilic conversion and photocatalytic activity. This is followed by the p-Ga2O3 and a-Ga2O3. The degraded performance in the p-Ga2O3 and a-Ga2O3 is attributed to the charge recombination. It is presumed that grain boundaries (GBs) and atomic disorder in the p-Ga2O3 and a-Ga2O3 create a broad energy distribution of the trap states in the forbidden band, serving as recombination centers for the photogenerated charge carriers. This is supported by the photoluminescence (PL) analysis. As well as fundamental science, the results of this work will contribute to practical applications such as self-cleaning, anti -fogging and antimicrobial activity.