Tin-assisted growth of ε-Ga2O3 film and the fabrication of photodetectors on sapphire substrate by PLD

The growth of single crystal epsilon-Ga2O3 films under the assistance of Sn element was studied using pulsed laser deposition (PLD). The crystal structure, optical properties and chemical state of the clement were investigated to analyze the influence of tin during the film epitaxy. There is a transition layer at the substrate and the epsilon-Ga2O3 film interface. Increase in Sn atomic ratio will cause a rise in the transition layer thickness and the growth rate. In addition, due to the Sn atoms aggregation and the formation of clusters, the higher dark current (I-dark), photocurrent (I-photo) and responsivity(R) were achieved for the enhanced electron transportation in the epsilon-Ga2O3 metal-semiconductor-metal (MSM) photodetectors. The optical bandgap E-g determined from R increased from 4.81eV to 4.88eV and 4.94eV with Sn contents increasing from 0.9% to 1.2% and 1.5%. consistent with the transmittance results. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement