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Polarization enhanced photoresponse of AlGaN p–i–n photodetectors
Author(s) -
Yang Lianhong,
Lai Kangrong,
Zhang Baohua,
Fu Xiaoling,
Wang Junjun,
Wei Wei
Publication year - 2015
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201431506
Subject(s) - photodetector , responsivity , photocurrent , optoelectronics , electric field , materials science , polarization (electrochemistry) , active layer , optics , layer (electronics) , physics , nanotechnology , chemistry , quantum mechanics , thin film transistor
We fabricated an enhanced photoresponse AlGaN p–i–n photodetector by introducing a polarization electric field along the growth direction into the active layer. The polarization‐enhanced effect was realized by reducing Al composition of the p‐AlGaN layer with respect to that of the i‐ and n‐type layers. The simulated results of energy‐band structure and electric‐field distribution indicate that the polarization‐enhanced structure can increase greatly the build‐in field in the active region and hence improve the collection efficiency of photogenerated carriers. The measured photocurrent spectra show that the polarization‐enhanced photodetector exhibits a nearly three times higher responsivity and a larger UV/visible contrast than its conventional counterpart.