Realizing Room‐Temperature Resonant Tunnel Magnetoresistance in Cr/Fe/MgAl
            2
            O
            4
            Quasi‐Quantum Well Structures

Room-temperature photovoltaic spectroscopy was applied to study undoped GaN, n-type GaN, and InGaN quantum well structures. Clear exciton absorption was observed in the photovoltaic spectra of the undoped GaN, and polarization measurements were made to identify the exciton absorption. For the n-type GaN sample, instead of the exciton absorption we observed only bulk absorption edge, which may be due to the free carrier screening effect. For the InGaN quantum well structures, the photovoltaic spectra showed relatively complicated line shape due to the overlap of the signals from different layers. By changing the reference phase of the lock-in amplifier, we were able to suppress some of the signals and thus identify the origin of the corresponding signal.

Download Full-text

Evidence of room‐temperature exciton by magnetophotoreflectance in epitaxial GaAs and quantum well structures

Applied Physics Letters ◽

10.1063/1.99249 ◽

1988 ◽

Vol 52 (12) ◽

pp. 984-986 ◽

Cited By ~ 15

Author(s):

X. L. Zheng ◽

D. Heiman ◽

B. Lax ◽

F. A. Chambers ◽

K. A. Stair

Keyword(s):

Quantum Well ◽

Room Temperature ◽

Quantum Well Structures ◽

Epitaxial Gaas

Download Full-text

Room temperature red light photoluminescence from AlGaAs multiple quantum well structures at very low excitation intensities

Journal of Vacuum Science & Technology B Microelectronics Processing and Phenomena ◽

10.1116/1.588848 ◽

1996 ◽

Vol 14 (3) ◽

pp. 2315

Author(s):

F. J. Towner

Keyword(s):

Quantum Well ◽

Room Temperature ◽

Red Light ◽

Multiple Quantum Well ◽

Multiple Quantum ◽

Quantum Well Structures

Download Full-text

Optical evaluation of pretreated InGaN quantum well structures

MRS Proceedings ◽

10.1557/proc-798-y5.59 ◽

2003 ◽

Vol 798 ◽

Author(s):

T. Böttcher ◽

F. Bertram ◽

P. Bergman ◽

A. Ueta ◽

J. Christen ◽

...

Keyword(s):

Quantum Well ◽

Quantum Wells ◽

Room Temperature ◽

Growth Direction ◽

Wetting Layer ◽

Quantum Well Structures ◽

Room Temperature Photoluminescence ◽

Decay Times ◽

Wavelength Distribution ◽

Ingan Quantum Wells

ABSTRACTIn order to optimize the quantum efficiency of InGaN quantum wells, different MOVPE growth sequences are compared using photo- and electroluminescence. In one study, the surface was pretreated with trimethylindium (TMIn) prior to the well deposition. In another study, growth interruptions were performed after the quantum well deposition to desorb segregated indium. In both cases, the room-temperature photoluminescence (PL) intensity is strongly enhanced. For the samples grown with TMIn preflow the wavelength distribution in low-temperature cathodoluminescence (CL) wavelength mappings is narrowed, which can be attributed to more homogeneous quantum wells. Furthermore, the decay times of the radiative recombination increase both at RT and 2K. A reason for this could be an improved indium profile along the growth direction or a more homogeneous In wetting layer due to the pre-wetted surface.

Download Full-text

Thermal Stability Study of Oxygen Implanted Algaas/Gaas Single Quantum Well Structures Using PhotoreflectancE

MRS Proceedings ◽

10.1557/proc-354-331 ◽

1994 ◽

Vol 354 ◽

Author(s):

P J Hughes ◽

E H Li ◽

B L Weiss ◽

H E Jackson ◽

J S Roberts

Keyword(s):

Thermal Stability ◽

Quantum Well ◽

Room Temperature ◽

Low Dose ◽

Stability Study ◽

Single Quantum ◽

Single Quantum Well ◽

Quantum Well Structures ◽

Annealing Conditions ◽

Thermal Stability Of

AbstractThe effects of interdiffusion on the band structure of two MxGaUxAs/GaAs single quantum well (SQW) structures were studied using room temperature photoreflectance. Rapid thermal annealing of the SQW structures at temperatures of 800°C, 900°C and 1000°C for times up to 180 seconds resulted in limited interdiffusion. Low dose (1014 cm”2) oxygen implantation reduced the thermal stability of these structures where the extent of the interdiffusion was found to be greater for the implanted samples for identical annealing conditions.

Download Full-text