Au-Nanoparticle-Assisted Pulsed-Laser Deposition of Ga 2 (O 1– x S x ) 3 Epitaxial Films

High Resolution Image Download MS PowerPoint Slide We report the impact of Au nanoparticles on the efficiency of S incorporation into β-Ga 2 O 3 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 Ga 2 (O 1– x S 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-Ga 2 O 3 through anion substitution with S.