DocumentCode :
786662
Title :
GaAs-based modulation-doped quantum-well infrared photodetectors for single- and two-color detection in 3-5 μm
Author :
Luna, Esperanza ; Guzmán, Álvaro ; Sdnchez-Rojas, J.L. ; Sánchez, Javier Miguel ; Muñoz, Elías
Author_Institution :
Dept. de Ingenieria Electron., Univ. Politecnica de Madrid, Spain
Volume :
8
Issue :
5
fYear :
2002
Firstpage :
992
Lastpage :
997
Abstract :
Double-barrier quantum-well infrared photodetectors are promising for operation in the midinfrared region. In this paper, we present a series of novel molecular beam epitaxy (MBE)-grown devices based on modulation-doped (MD) AlGaAs-AlAs-GaAs structures that exhibit a remarkable responsivity at zero bias (0.05 A/W) at 4.6 μm. Since the photovoltaic properties are strongly dependent on the symmetry of the potential profile, we have systematically varied the position of the dopant in the barriers for a series of single-color detectors. Low-temperature photocurrent spectra and current-voltage (I-V) characteristics (in the dark and under illumination) show that the location of the dopant is a relevant design parameter, due to its role in the photovoltaic behavior (i.e., the presence or absence of zero bias signal). The performance of the MD devices is compared with that of a detector with doping in the center of the well and otherwise the same structure. In particular, the responsivity and detectivity seem to be higher for the MD detectors than for well-doped samples, especially when the dopant is located in the barrier closest to the substrate. Therefore, we have chosen that MD dopant profile when designing and growing, to our knowledge, the first 3-5 μm two-color detector, with simultaneous detection at 3.8 and 4.4 μm.
Keywords :
III-V semiconductors; aluminium compounds; doping profiles; gallium arsenide; infrared detectors; molecular beam epitaxial growth; photodetectors; quantum well devices; semiconductor growth; semiconductor quantum wells; 3 to 5 micron; 3.8 micron; 4.4 micron; 4.6 micron; AlGaAs-AlAs-GaAs; GaAs-based modulation-doped quantum-well infrared photodetectors; current-voltage characteristics; dark; design parameter; designing; detectivity; dopant position; dopant profile; double-barrier quantum-well infrared photodetectors; illumination; low-temperature photocurrent spectra; midinfrared region; modulation-doped AlGaAs-AlAs-GaAs structures; molecular beam epitaxy grown devices; photovoltaic properties; potential profile symmetry; responsivity; single-color detection; substrate; two-color detection; zero bias; Epitaxial layers; Infrared detectors; Lighting; Molecular beam epitaxial growth; Photoconductivity; Photodetectors; Photovoltaic systems; Quantum well devices; Quantum wells; Solar power generation;
fLanguage :
English
Journal_Title :
Selected Topics in Quantum Electronics, IEEE Journal of
Publisher :
ieee
ISSN :
1077-260X
Type :
jour
DOI :
10.1109/JSTQE.2002.804240
Filename :
1097850
Link To Document :
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