Study of photoresponsivity in optoelectronic devices based on single crystal β-Ga_2O_3 epitaxial layers

摘要

Single crystal β-Ga_2O_3 epitaxial layers have been prepared on c-axis (0001) sapphire substrates using metalorganic chemical vapor deposition technique at relatively low temperature. Post-annealing of β-Ga_2O_3 single crystals up to 800 ℃ does not affect the crystallinity, explored by x-ray diffraction, showing that P-Ga_2O_3 epitaxial layers are highly (-201) oriented. Metal-semiconductor-metal devices are fabricated on single crystals to study their photoresponsivity. A significant improvement in performance of post annealed-based devices is observed, attributed to point defect reduction. Annealing of as-grown samples results to a significant decrease in both oxygen and gallium vacancies, which are sources of current leakage.