Analysis of dark currents and deep level traps in InP- and GaAs-based In0.83Ga0.17As photodetectors

• Published in: Journal of crystal growth 2017-11, Vol.477, p.82-85
• Main Authors: Chen, X.Y., Zhang, Y.G., Gu, Y., Ji, X.L., Xi, S.P., Du, B., Ma, Y.J., Ji, W.Y., Shi, Y.H., Li, A.Z.
• Format: Article
• Language: English
• Subjects: A1: Defects; A3: Molecular beam epitaxy; B2: Semiconducting III–V materials; B3: Infrared devices
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2017.02.041

•InP- and GaAs-based In0.83Ga0.17As photodetectors were grown by GSMBE.•GaAs-based photodetector shows higher dark current than InP-based photodetector.•DLTS reveals a deep level trap state in the GaAs-based photodetector.•Deep level trap induces higher tunneling current in GaAs-based photodetector. InP- and GaAs-based metamorphic In0.83Ga0.17As photodetectors were grown and investigated. Compared to InP-based photodetector, the dark current of GaAs-based photodetector at room temperature increased 2–3 times but still comparable, whereas at 77K the dark current increased 2–3 orders. The deep-level transient spectroscopy results reveal that a deep level trap state exists in the GaAs-based photodetector structure. The higher dark current in GaAs-based photodetector at low temperature was mainly ascribed to a deep level trap induced tunneling current. The deep trap centers can also induce non-radiative recombination with smaller thermal active energy in the GaAs-based photodetector structure.