Currie M, Dianat P, Persano A, Martucci MC, Quaranta F, Cola A, Nabet B. Performance enhancement of a GaAs detector with a vertical field and an embedded thin low-temperature grown layer.
Sensors (Basel) 2013;
13:2475-83. [PMID:
23429510 PMCID:
PMC3649398 DOI:
10.3390/s130202475]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 02/06/2013] [Accepted: 02/08/2013] [Indexed: 11/21/2022]
Abstract
Low temperature growth of GaAs (LT-GaAs) near 200 °C results in a recombination lifetime of nearly 1 ps, compared with approximately 1 ns for regular temperature ∼600 °C grown GaAs (RT-GaAs), making it suitable for ultra high speed detection applications. However, LT-GaAs detectors usually suffer from low responsivity due to low carrier mobility. Here we report electro-optic sampling time response measurements of a detector that employs an AlGaAs heterojunction, a thin layer of LT-GaAs, a channel of RT-GaAs, and a vertical electric field that together facilitate collection of optically generated electrons while suppressing collection of lower mobility holes. Consequently, these devices have detection efficiency near that of RT-GaAs yet provide pulse widths nearly an order of magnitude faster—∼6 ps for a cathode-anode separation of 1.3 μm and ∼12 ps for distances more than 3 μm.
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