【Epitaxy Papers】Au-Nanoparticle-Assisted Pulsed-Laser Deposition of Ga₂(O₁₋ₓSₓ)₃ Epitaxial Films

      Researchers from the Institute of Science Tokyo have published a dissertation titled "Au-Nanoparticle-Assisted Pulsed-Laser Deposition of Ga₂(O_1–xS_x)₃ Epitaxial Films" in Crystal Growth & Design.

Abstract

      We report the impact of Au nanoparticles on the efficiency of S incorporation into β-Ga₂O₃ films grown on (100) MgO substrates by pulsed-laser deposition (PLD) with GaS as a solid source. Prior to PLD, thin Au layers were vacuum-deposited and dewetted. The dewetted Au layers were transformed into fine nanoparticles, which significantly facilitated not only the sulfurization of Ga but also the growth rate at growth temperatures (T_g) higher than 600 °C. As a result, (100)-oriented Ga₂(O_1–xS_x)₃ films with x as high as 0.38 were obtained. Despite notable compositional fluctuations, the band gap energy was tuned from 3.7 to 4.4 eV by changing T_g and Au-layer thickness. Moreover, we revealed that the amount of effective Au nanoparticles, measured from the dependence of S content in the films on equivalent Au-layer thickness, was in a range from 0.4 to 1.5 nm. These results indicate that Au-nanoparticle-assisted PLD is a useful method for the band gap engineering of β-Ga₂O₃ through anion substitution with S.

DOI：

https://doi.org/10.1021/acs.cgd.5c01584