Growth and Characterization of Interfaces in P-Type InGaAs/InP Quantum-Well Infrared Photodetectors with Ultra-Thin Quantum Wells

ABSTRACTP-type InGaAs/InP quantum-well infrared photodetectors operated at 4.55 μm require the growth of ultra-thin (10 Å) quantum wells. We report a study of interfaces in QWIPs grown by gas-source molecular beam epitaxy in which we optimized the group V source supply sequence so that a 6 K photoluminescence linewidth as narrow as 8.4 meV was observed from a structure with 10 Å wells. Analysis of the PL suggests that interface roughness was minimized. Cross-sectional scanning tunneling microscopy, double crystal x-ray diffraction, and cross-sectional tunneling electron microscopy confirmed that high-quality interfaces and uniform layers were obtained. Using the derived structural parameters, photocurrent spectral response was theoretically predicted for these QWIPs and then experimentally verified.

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P-Type Quantum Well Infrared Photodetectors Grown by OMVPE

MRS Proceedings ◽

10.1557/proc-240-569 ◽

1991 ◽

Vol 240 ◽

Cited By ~ 1

Author(s):

W. S. Hobson ◽

A. Zussman ◽

J. De Jong ◽

B. F. Levine

Keyword(s):

Quantum Well ◽

Quantum Wells ◽

Normal Incidence ◽

Infrared Photodetectors ◽

Cutoff Wavelength ◽

Peak Wavelength ◽

Long Wavelength ◽

Quantum Well Infrared Photodetectors ◽

Intersubband Absorption ◽

P Type

ABSTRACTWe report on the growth and fabrication of p-doped long wavelength GaAs/AlxGa1−x As quantum well infrared photodetectors (QWIP) grown by organometallic vapor phase epitaxy. The operation of these devices is based on the photocurrent induced through valence band intersubband absorption by holes and, unlike n-doped QWIPs, can utilize normal incidence illumination. Carbon and zinc were used as the p-type dopants in a low-pressure (30 Torr) vertical-geometry reactor. The Zn-doped QWIP consisted of fifty periods of 48 nm-thick undoped Al0.36Ga0.64As barriers and nominally 4 nm-thick doped GaAs quantum wells. Using normal incidence, a quantum efficiency of η = 2.5% and a detectivity of at 77K were obtained for a peak wavelength λp = 6.8 μm and a cutoff wavelength λ∫ =7.6 μm. The C-doped QWIP had 54 nm-thick Al0.31Ga0.69As barriers and exhibited a normal incidence These initial studies indicate the superiority of carbon to zinc as the p-type dopant for these structures. The detectivity of the C-doped QWIPs is about four times less than n-doped QWIPs for the same λp but have the advantage of utilizing normal incidence illumination.

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Comparison of N- And P-Type Ingaas/Inp Quantum Well Infrared Photodetectors

MRS Proceedings ◽

10.1557/proc-421-203 ◽

1996 ◽

Vol 421 ◽

Author(s):

D.K. Sengupta ◽

J.I. Malin ◽

S.L. Jackson ◽

W. Fang ◽

W. Wu ◽

...

Keyword(s):

Quantum Well ◽

Spectral Response ◽

Growth Conditions ◽

Dual Band ◽

Infrared Photodetectors ◽

Quantum Well Infrared Photodetectors ◽

Gas Source ◽

Order Of Magnitude ◽

P Type ◽

Lattice Matched

AbstractOver an order of magnitude reduction in dark current was observed for gas-source molecular beam epitaxially (GSMBE) grown, lattice-matched n- and p-type InGaAs/InP quantum-well infrared photodetectors (QWIPs). Peak spectral response at 8.93 and 4.55 μm for n- and p-type QWIPs, respectively, open the possibility of dual-band monolithic integration under identical GSMBE growth conditions.

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