Light Emission Properties of GaN-Based Double Heterostructures and Quantum Wells

1995 ◽  
Vol 395 ◽  
Author(s):  
D.A.S. Loeber ◽  
J.M. Redwing ◽  
N.G. Anderson ◽  
M.A. Tischler
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Stimulated Emission ◽  
Pump Light ◽  
Band Edge Emission ◽  
Emission Characteristics ◽  
Nitrogen Laser ◽  
Edge Emission ◽  
Edge Luminescence ◽  
Double Heterostructures

ABSTRACTEdge emission characteristics of optically pumped GaN-AlGaN double heterostructures and quantum wells are examined. The samples, which were grown by metalorganic vapor phase epitaxy, are photoexcited with light from a pulsed nitrogen laser. The pump light is focused to a narrow stripe on the sample surface, oriented perpendicular to a cleaved edge, and the edge luminescence is collected and analyzed. We first compare emission characteristics of highly excited GaN-AlGaN double heterostructures grown simultaneously on SiC and sapphire substrates. Polarization resolved spectral properties of edge luminescence from both structures is studied as a function of pump intensity and excitation stripe length. Characteristics indicative of stimulated emission are observed, particularly in the sample grown on SiC. We then present results demonstrating laser emission from a GaN-AlGaN separate-confinement quantum-well heterostructure. At high pump intensities, band edge emission from the quantum well exhibits five narrow (∼1 Å) modes which are evenly spaced by 10Å to within the resolution of the spectrometer. This represents the first demonstration of laser action in a GaN-based quantum-well structure.

Stimulated Emission from Single- and Multiple-Quantum-Well GaN-AlGaN Separate-Confinement Heterostructures

1996 ◽  
Vol 449 ◽  
Author(s):  
D. A. S. Loeber ◽  
N. G. Anderson ◽  
J. M. Redwing ◽  
J. S. Flynn ◽  
G. M. Smith ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Optical Pumping ◽  
Multiple Quantum Well ◽  
Emission Spectra ◽  
Stimulated Emission ◽  
Emission Characteristics ◽  
Multiple Quantum ◽  
Photoluminescence Properties ◽  
Single Quantum Well

ABSTRACTStimulated emission characteristics are examined for GaN-AlGaN separate-confinement quantum-well heterostructures grown by MOVPE on 4H-SiC substrates. We specifically focus on comparison of structures with different quantum well active region designs. Polarization resolved edge emission spectra and stimulated emission thresholds are obtained under optical pumping using a stripe excitation geometry. Stimulated emission characteristics are studied as a function of the number of quantum wells in the structure, and are correlated with surface photoluminescence properties. We find reduced stimulated emission thresholds and increased surface photoluminescence intensities as the number of quantum wells is reduced, with the best results obtained for a single-quantum-well structure. These results should provide useful information for the design of GaN-based quantum well lasers.

Stimulated emission characteristics of InGaN/GaN multiple quantum wells: Excitation length and excitation density dependence

1998 ◽  
Vol 73 (25) ◽  
pp. 3689-3691 ◽  
Author(s):  
T. J. Schmidt ◽  
S. Bidnyk ◽  
Yong-Hoon Cho ◽  
A. J. Fischer ◽  
J. J. Song ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Density Dependence ◽  
Stimulated Emission ◽  
Multiple Quantum Wells ◽  
Excitation Density ◽  
Emission Characteristics ◽  
Multiple Quantum

Influence of template properties and quantum well number on stimulated emission from Al0.7Ga0.3N/Al0.8Ga0.2N quantum wells

2018 ◽  
Vol 33 (3) ◽  
pp. 035015 ◽  
Author(s):  
J Jeschke ◽  
M Martens ◽  
S Hagedorn ◽  
A Knauer ◽  
A Mogilatenko ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Stimulated Emission

AES and EELFS Studies of Initial Stages of Growth of GaAs/InAs/GaAs Heterostructures.

1988 ◽  
Vol 144 ◽  
Author(s):  
F. D. Schowengerdt ◽  
F. J. Grunthaner ◽  
John K. Liu
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Growth Parameters ◽  
High Energy ◽  
Model Calculations ◽  
Mbe Growth ◽  
Quantum Well Structures ◽  
Stages Of Growth ◽  
Double Heterostructures ◽  
Composition And Structure

ABSTRACTWe report on a systematic study of the composition and structure of GaAs/InAs/GaAs quantum wells using Auger Electron Spectroscopy (AES), Extended Energy Loss Fine Structure (EELFS), and Reflection High Energy Electron Diffraction (RHEED) techniques. Double heterostructures with InAs thickness ranging from 2 to 10 monolayers, capped by 2 to 10 monolayers of GaAs, were grown by MBE using a variety of techniques, including those employing sequential, interrupted, and delayed shutter timing sequences. AES peak ratios are compared with model calculations to monitor compositional development of the multilayers. The AES results are correlated with RHEED measurements to determine MBE growth parameters for optimal control of the stoichiometry and surface morphology. EELFS was used to monitor strain in the buried InAs layers. The AES results show departure from smooth laminar growth of layers of stoichiometric InAs on GaAs at temperatures below 420 C and above 470 C. AES results on the quantum well structures suggest floating InAs layers on top of the GaAs and/or facet formation in the GaAs layers. The EELFS results, when compared to bulk InAs, indicate the presence of strain in the buried InAs quantum well.

Growth of High Quality InGaN Films by Metalorganic Chemical Vapor Deposition

1995 ◽  
Vol 395 ◽  
Author(s):  
J. C. Roberts ◽  
F. G. McIntosh ◽  
K. S. Boutros ◽  
S. M. Bedair ◽  
M. Moussa ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Visible Spectrum ◽  
Band Edge Emission ◽  
X Ray Diffraction ◽  
Edge Emission ◽  
Sapphire Substrates ◽  
Mocvd Growth ◽  
Double Heterostructures ◽  
High Vapor ◽  
Line Widths

ABSTRACTInGaN based optical devices can cover from the violet through orange regions of the visible spectrum. Difficulties in the growth of this alloy, which have impeded its applications, include problems such as the high vapor pressure of In, weak In-N bonds and lack of sufficient nitrogen during growth. We report on the MOCVD growth of InxGa1−xN (0 < x < 0.4) on sapphire substrates in the 750 - 800 °C temperature range. X-ray diffraction data show full width at half maximum line widths as narrow as 250 arcsec for low values of x, while films with higher lnN% exhibit broader line widths. Room temperature photoluminescence spectra exhibit band edge emission, with emission from deep levels increasing with x. Preliminary investigations of AlGaN/lnGaN/AlGaN double heterostructures have been conducted.

Optical Properties of Pseudomorphic InxGa1−xAs Quantum Wells

1986 ◽  
Vol 77 ◽  
Author(s):  
N. G. Anderson ◽  
Y. C. Lo ◽  
R. M. Kolbas
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Excitation Intensity ◽  
Stimulated Emission ◽  
Luminescence Properties ◽  
Photoluminescence Spectra ◽  
Quantum Well Structures ◽  
Single Feature ◽  
Increasing Temperature ◽  
Confining Layers

ABSTRACTThe luminescence properties of MBE-grown pseudomorphic InxGa1−xAs—GaAs quantum-well structures are examined as a function of photoexcitation intensity and temperature. The structures examined consist of single In0.28Ga0.72As or (isolated) multiple In0.16Ga0.84As pseudomorphic wells sandwiched between thick, unstrained GaAs confining layers. Low-temperature photoluminescence spectra for these samples, which range in quantum-well thickness from 17 Å to 50 Å, consist of a single feature attributable to transitions associated with n = 1 electron and j = 3/2, Mj = 3/2 > - hole states. Spectral widths of these peaks are very narrow (7–11 meV), even for a heavily spike-doped sample (Si, ND ∼ 1018 spike-doped at well center). Emission intensities for the quantum-well structures are studied as a function of excitation intensity over the range 3 × 102 ≤ Pex ≤ 6 x 1O4 W/cm2, and one of the samples (x = 0.16, 50 Å undoped wells) prepared as a laser structure is shown to support stimulated emission at an excitation intensity < 104 W/cm2. The excellent luminescence properties of these structures are shown to degrade rapidly with increasing temperature, with radiative efficiencies dropping more than two orders of magnitude over the temperature range 20K – 180K. One possible explanation for this behavior is proposed.

scholarly journals The role of piezoelectric fields in GaN-based quantum wells

1998 ◽  
Vol 3 ◽  
Author(s):  
Andreas Hangleiter ◽  
Jin Seo Im ◽  
H. Kollmer ◽  
S. Heppel ◽  
J. Off ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Spatial Separation ◽  
Stimulated Emission ◽  
Wurtzite Phase ◽  
Single Quantum Well ◽  
Quantum Well Structures ◽  
Free Case ◽  
Piezoelectric Field ◽  
Piezoelectric Fields

In this contribution, we focus on the consequences of the piezoelectric field, which is an inherent consequence of the commonly used wurtzite phase of GaN, on the optical properties of strained GaN-based quantum well structures. We demonstrate that both in GaN/AlGaN and in GaInN/GaN single quantum well structures, the piezoelectric field leads to a Stark-shift of the fundamental optical transitions, which can lead to luminescence emission far below the bulk bandgap. Due to the spatial separation of the electron and hole wavefunctions in such structures, the oscillator strength of these transitions may become extremely small, many orders of magnitude lower than in the field-free case. From specially designed structures, we can even determine the sign of the piezoelectric field and relate it to the polarity of the layers. Under high-excitation conditions, as found in a laser diode, the piezoelectric field is almost completely screened by the injected carriers. As a consequence, the stimulated emission is significantly blue-shifted compared to the photoluminescence, which has sometimes been confused with localization effects.

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