Open AccessComparison Study of β-Ga2O3 Photodetectors Grown on Sapphire at Different Oxygen Pressures
Author(s) -
Lu Huang,
Qian Feng,
Genquan Han,
Fuguo Li,
Xiang Li,
Liwei Fang,
Xiangyu Xing,
Jincheng Zhang,
Yue Hao
Publication year - 2017
Publication title -
ieee photonics journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.725
H-Index - 73
eISSN - 1943-0655
pISSN - 1943-0647
DOI - 10.1109/jphot.2017.2731625
Subject(s) - engineered materials, dielectrics and plasmas , photonics and electrooptics
In this paper, β-Ga2O3 ultraviolet photodetectors were grown on sapphire utilizing the laser molecular beam epitaxy tool. The impact of oxygen pressure PO2 in growth chamber on the crystal quality, the surface morphology, the chemical component of Ga2O3 films, and the electrical performance of photodetectors are characterized. As the PO2 is increased during growth, the concentration of oxygen vacancy (VO) is effectively reduced. The photodetector grown at the PO2 of 0.05 mbar exhibits the significantly improved photocurrent Iphoto and responsivity R characteristics in comparison with the device grown with the PO2 of 0.01 mbar, which is attributed to a reduction in the number of VO. However, as the PO2 continuously increased to 0.09 mbar, Iphoto and R of the detector are degraded, which might be due to the fact that the gallium vacancies (VGa), as the dominant trapping centers, lead to the recombination of photo-generated carriers.