Time-resolved photoluminescence studies of InGaN/GaN multiple quantum wells

1997 ◽  
Vol 2 ◽  
Author(s):  
J. Allègre ◽  
P. Lefebvre ◽  
S. Juillaguet ◽  
W. Knap ◽  
J. Camassel ◽  
...  
Keyword(s):  
Low Temperature ◽  
Quantum Wells ◽  
Multiple Quantum Well ◽  
Stimulated Emission ◽  
Multiple Quantum ◽  
Nitrogen Laser ◽  
Energy Position ◽  
Blue Band ◽  
Time Resolved ◽  
Decay Times

We report both cw and time resolved optical investigations performed on an InGaN/GaN multiple quantum well grown by MOVPE on <0001>-oriented sapphire substrate. At low temperature we find a strong “blue” luminescence band, of which energy position corresponds well with the wavelength of stimulated emission when excited with a nitrogen laser. We show that this PL band appears systematically red-shifted with respect to the QWs features, which supports a standard picture of fluctuations of the indium composition. Coming to the time-resolved data, we find at low temperature at least two “blue” band components which are both associated with long decay times (up to 4-5 ns at 8K). The decay time is temperature dependent and, when rising the temperature, the recombination rate increases. At room temperature, we reach typical values in the range ~100 to 500 ps.

scholarly journals Photo- and cathodoluminescence investigations of piezoelectric GaN/AlGaN quantum wells

2000 ◽  
Vol 639 ◽  
Author(s):  
E.M. Goldys ◽  
M. Godlewski ◽  
M.R. Phillips ◽  
A.A. Toropov
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Electric Fields ◽  
Free Exciton ◽  
Multiple Quantum Well ◽  
Depth Profiling ◽  
Multiple Quantum ◽  
Recombination Mechanism ◽  
Decay Times ◽  
Piezoelectric Fields

ABSTRACTWe have examined multiple quantum well AlGaN/GaN structures with several quantum wells of varying widths. The structures had strain-free quantum wells and strained barriers. Strong piezoelectric fields in these structures led to a large red shift of the PL emission energies and long decay times were also observed. While the peak energies could be modelled using the effective mass approximation, the calculated free exciton radiative lifetimes were much shorter than those observed in experiments, indicating an alternative recombination mechanism, tentatively attributed to localised excitons. Cathodoluminescence depth profiling revealed an unusually small penetration range of electrons suggesting that electron-hole pairs preferentially remain within the multiple quantum well region due to the existing electric fields. Spatial fluctuations of the cathodoluminescence intensity were also observed.

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.

Optical Properties of Ingan/GaN Multi Quantum Well Structures

1997 ◽  
Vol 482 ◽  
Author(s):  
J. P. Bergman ◽  
N. Saksulv ◽  
J. Dalfors ◽  
P. O. Holtz ◽  
B. Monemar ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Multiple Quantum ◽  
Recombination Rates ◽  
Energy Position ◽  
Electron Hole ◽  
Time Resolved ◽  
Quantum Well Structures ◽  
Lower Energy Band ◽  
Time Resolved Photoluminescence ◽  
Multi Quantum Well

AbstractA set of GaN/InGaN multiple quantum wells (QWs) with well thickness 30 Å and barrier thickness 60 Å were grown by MOCVD on sapphire substrates. The n-type Si doping of the InGaN QWs was varied, in order to produce a different electron concentration in the QWs for the different samples. Optical spectra were obtained by time resolved photoluminescence spectroscopy. The data show weak excitonic spectra from the QWs as well as a broad deeper emission with a much stronger intensity. The spectral shape becomes narrower and the energy position shifts to higher energies with increasing doping. The two different emissions are not easily separated in CW or time integrated spectra, but are clearly observed in a time resolved spectral measurement due to their different recombination rates. The deeper emission has a long and non-exponential decay, with an average decay time in the order of several hundred nanoseconds. The higher energy exciton emission has a much faster decay of about 1 ns. The lower energy band is tentatively explained as due to separately localized electron-hole (e-h) pairs in the QW.

Temperature Dependent and Time Resolved Optical Studies of Single Quantum Wells Produced by Interrupted Growth MBE

1986 ◽  
Vol 77 ◽  
Author(s):  
B. S. Elman ◽  
Emil S. Koteles ◽  
C. Jagannath ◽  
Y. J. Chen ◽  
S. Charbonneau ◽  
...  
Keyword(s):  
Low Temperature ◽  
Quantum Wells ◽  
Single Quantum ◽  
Temperature Dependent ◽  
Time Resolved ◽  
Molecular Beam Epitaxial ◽  
Decay Times ◽  
Higher Temperature ◽  
The Individual ◽  
Molecular Beam Epitaxial Growth

ABSTRACTMultiple peaks, recently observed in the low temperature photoluminescence (PL) spectra of GaAs/AlGaAs single quantum wells fabricated by momentarily interrupting the molecular beam epitaxial growth between adjacent but different semiconductor layers, have been interpreted as originating within smooth regions in the quantum well layer differing in width by exactly one monolayer. We have observed similar structure in similarly grown samples but find that low temperature PL can be misleading. However, higher temperature PL or PL excitation spectroscopy do provide unambiguous evidence for the model of interface smoothing due to growth interruption. Further, time-resolved spectra yield decay times of the individual peaks which are consistent with this idea.

Optical Properties of Zn0.46Cd0.54Se/Zn0.24Cd0.25Mg0.51Se Multiple Quantum Wells for Infrared Photodetector Applications

2006 ◽  
Vol 952 ◽  
Author(s):  
Xuecong Zhou ◽  
Shengkun Zhang ◽  
Hong Lu ◽  
Aidong Shen ◽  
Wubao Wang ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Cascade Lasers ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Infrared Photodetector ◽  
Temperature Dependent ◽  
Time Resolved ◽  
Mid Infrared ◽  
Luminescence Efficiency ◽  
Decay Times

ABSTRACTRecently, lattice-matched Zn0.46Cd0.54Se/ZnCdMgSe multiple-quantum-wells (MQWs) have been recognized as very promising materials to fabricate intersubband (ISB) devices such as quantum cascade lasers and mid-infrared photoconductors. These structures have important applications in biological and chemical detections. The ISB transition covers a wide mid-infrared wavelength range from 1.3 μm to a few tens of μm.In this work, two heavily doped n-Zn0.46Cd0.54Se/Zn0.24Cd0.25Mg0.51Se MQW structures have been grown on InP (001) substrate by molecular beam epitaxy. Temperature dependent steady-state photoluminescence (SSPL), temperature dependent time- resolved photoluminescence (TRPL), and Fourier transform infrared spectroscopy (FTIR) were performed to characterize their interband and ISB properties. These two MQW samples have similar structures except different well widths and different number of periods. The integrated SSPL intensities and the PL decay times of the MQWs were measured as functions of temperature in the range from 77 K to 290 K. The luminescence efficiency of the sample with 28 Å well width is larger than that of the sample with 42 Å well width although both samples exhibit similar temperature dependence of PL intensity. Time-resolved PL measurements show that the PL decay times of both samples decrease with increasing temperature. From 77 K to 290 K, the decay time of the sample with 28 Å well width is in the range of 440 ps ∼ 120 ps and is much longer than that of the sample with 42 Å well width, which is in the range of 65 ps ∼ 25 ps. Strong non-radiative recombinations dominate the luminescence behavior of the wider MQWs. Intersubband absorption spectra of the samples were measured by FTIR and show peak absorption at wavelengths of 3.99 μm and 5.35 μm for the MQWs with well widths of 28 Å and 42 Å, respectively, falling within the 3-5 Åm range, which is of great interest for the infrared photodetector applications.

High-temperature crystallinity restoring layers and their optimal positions for ultra-thick InGaN/GaN multiple-quantum-well structures

CrystEngComm ◽  
2021 ◽  
Author(s):  
Yu Guo ◽  
Huanqing Chen ◽  
Rui Lang ◽  
Menglai Lei ◽  
Hua Zong ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Quantum Well ◽  
Quantum Wells ◽  
Multiple Quantum Well ◽  
Crystal Quality ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Quantum Well Structures ◽  
Progressive Deterioration

Maintaining crystal quality during the growth of very thick multiple-quantum-wells is challenging due to the progressive deterioration in thick low-temperature barriers. The insertion of several high-temperature crystallinity restoring (CR) layers...

Band Offsets of InAsxP1−X/InP Strained Layer Quantum Wells Grown by Lp-Movpe Using TBAs

1994 ◽  
Vol 358 ◽  
Author(s):  
M. Beaudoin ◽  
R.A. Masut ◽  
L. Isnard ◽  
P. Desjardins ◽  
A. Bensaada ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Absorption Spectra ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Energy Position ◽  
Band Offsets ◽  
Quantum Well Structures ◽  
Strained Layer ◽  
Transmission Electron ◽  
Metal Organic

ABSTRACTLow temperature optical absorption spectra are presented for a series of InAsxP1-x/InP strained layer multiple quantum well structures (0 < x = 0.35) grown by low pressure metal organic vapor phase epitaxy (LP-MOVPE) using trimethylindium (TMIn), tertiarybutylarsine (TBAs) and phosphine as precursors. The well widths and compositions in these structures are determined from high resolution x-ray diffraction and transmission electron microscopy. The absorption spectra are then analyzed by fitting the excitonic peak energy position with transition energies determined from a solution to the Schrödinger equation. We used the envelope function formalism with the Kane bands as the basis wavefunctions and included corrections for non parabolicity. From these fits and elasticity theory, both the bandgap of unstrained InAsxP1-x and the band offsets of these heterostructures are deduced self-consistently. The conduction band offsets are found between 72% and 75% of the total strained bandgap differences.

Similarities in the Optical Properties of Hexagonal and Cubic InGaN Quantum Wells

2001 ◽  
Vol 693 ◽  
Author(s):  
S. F. Chichibu ◽  
M. Sugiyama ◽  
T. Onuma ◽  
T. Kuroda ◽  
A. Tackeuchi ◽  
...  
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Multiple Quantum Well ◽  
Intrinsic Property ◽  
Multiple Quantum ◽  
Time Resolved ◽  
Exciton Localization ◽  
Peak Energy ◽  
Stretched Exponential Decay ◽  
Ingan Quantum Wells

AbstractOptical properties of fully-strained wurtzite and zincblende InxGa1-xN/GaN multiple quantum well (MQW) structures were compared to discuss the origin of exciton localization. In contrast to the hexagonal InGaN MQWs, the photoluminescence (PL) peak energy of cubic InGaN MQWs showed a moderate blueshift with decreasing well thickness, L, and low-temperature PL decay time of the cubic MQWs did not depend strongly on L. The results imply that the wavefunction overlap in cubic InGaN MQWs was not reduced compared to the hexagonal ones, since they do not suffer from the electric field normal to the QW plane due either to spontaneous or piezoelectric polarization. Both MQWs exhibited a large and composition-dependent bandgap bowing, and time-resolved PL (TR-PL) signals showed a stretched-exponential decay even at room temperature. The exciton localization is considered to be an intrinsic property of InGaN.

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.

Sign in / Sign up

Export Citation Format

Share Document