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Proceedings Paper

Photo-and-dark-current-voltage characteristics of normal-incidence GaAs photodetectors with two types of electrode configurations
Author(s): Xiuhuan Liu; Mingli Li; Zhanguo Chen; Gang Jia; Tianliang Bian; Yi Li
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Paper Abstract

The characteristics of photo-current-voltage and dark-current-voltage for two-photon-response semi-insulating GaAs photodetectors responding to near-infrared wavelengths of 1.31 μm and 1.55μm are investigated. The semi-insulating GaAs photodetectors were fabricated into hemisphere on whose bottom two types of electrodes were deposited. In experiments, the incident laser was adjusted to travel normally to the photodetector and focus at the center of the bottom so as to improve the nonlinear photo-responsivity markedly. It is observed that the photocurrent dependent on bias exhibits quadratic nonlinearity for both lasers and both electrode configurations, which reflects frequency-doubled absorption responsible for the physical mechanisms of the photodetectors; and the reasonable analysis demonstrates the important role of the electric-field-induced frequency-doubled absorption in two-photon response. Furthermore, it is found that the photocurrent is quite more greater when the electrode positioned at the bottom center of the photodetectors (central electrode for short) is negatively charged than that in the case of it positively charged under the conditions of the identical bias voltage and the same incident optical power; while the dark-current varies in exactly the opposite mode compared to the photocurrent. The aforementioned disparate variations of the photocurrent and the dark-current are well interpreted by the theory of surface band-bending of semi-insulating GaAs, and such variations result in a large ratio of photo-current to dark-current in the case of the central electrode negatively charged. The investigated results also indicate that the optimization of electrode structure is essential to improve the photo-responsivity of the photodetector.

Paper Details

Date Published: 13 April 2015
PDF: 8 pages
Proc. SPIE 9522, Selected Papers from Conferences of the Photoelectronic Technology Committee of the Chinese Society of Astronautics 2014, Part II, 952220 (13 April 2015); doi: 10.1117/12.2180320
Show Author Affiliations
Xiuhuan Liu, Jilin Univ. (China)
Mingli Li, Jilin Univ. (China)
Zhanguo Chen, Jilin Univ. (China)
Gang Jia, Jilin Univ. (China)
Tianliang Bian, Jilin Univ. (China)
Yi Li, Jilin Univ. (China)

Published in SPIE Proceedings Vol. 9522:
Selected Papers from Conferences of the Photoelectronic Technology Committee of the Chinese Society of Astronautics 2014, Part II
Xiangwan Du; Jennifer Liu; Dianyuan Fan; Jialing Le; Yueguang Lv; Jianquan Yao; Weimin Bao; Lijun Wang, Editor(s)

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