Numerical Analysis of Time Resolved Photoluminescence for Alumina/Cd(Se,Te) Double Heterostructures

2021 ◽  
Author(s):  
Jordan R. Fox ◽  
Darius Kuciauskas ◽  
David S. Albin ◽  
Marco Nardone
Keyword(s):  
Numerical Analysis ◽  
Time Resolved ◽  
Double Heterostructures ◽  
Time Resolved Photoluminescence

Epitaxial Growth and Luminescence Characterization of Si-based Double Heterostructures Light-emitting Diodes with Iron Disilicide Active Region

2006 ◽  
Vol 958 ◽  
Author(s):  
Takashi Suemasu ◽  
Cheng Li ◽  
Tsuyoshi Sunohara ◽  
Yuta Ugajin ◽  
Ken'ichi Kobayashi ◽  
...  
Keyword(s):  
Decay Time ◽  
Room Temperature ◽  
Time Resolved ◽  
Iron Disilicide ◽  
Light Emitting ◽  
Si Substrates ◽  
Carrier Recombination ◽  
Double Heterostructures ◽  
Time Resolved Photoluminescence

ABSTRACTWe have epitaxially grown Si/β-FeSi2/Si (SFS) structures with β-FeSi2 particles or β-FeSi2 continuous films on Si substrates by molecular beam epitaxy (MBE), and observed 1.6 μm electroluminescence (EL) at room temperature (RT). The EL intensity increases with increasing the number of β-FeSi2 layers. The origin of the luminescence was discussed using time-resolved photoluminescence (PL) measurements. It was found that the luminescence originated from two sources, one with a short decay time (τ∼10 ns) and the other with a long decay time (τ∼100 ns). The short decay time was due to carrier recombination in β-FeSi2, whereas the long decay time was due probably to a defect-related D1 line in Si.

Spontaneous and Stimulated Recombination in the Nitrides

1996 ◽  
Vol 449 ◽  
Author(s):  
A. Hangleiter ◽  
F. Scholz ◽  
V. Härle ◽  
J. S. Im ◽  
G. Frankowsky
Keyword(s):  
Quantum Wells ◽  
Room Temperature ◽  
Optical Gain ◽  
Stimulated Emission ◽  
Time Resolved ◽  
Double Heterostructures ◽  
Bulk Gan ◽  
Photoluminescence Studies ◽  
Excitonic Effects ◽  
Time Resolved Photoluminescence

ABSTRACTBoth spontaneous and stimulated emission processes are essential ingredients for constructing a laser from the nitrides. Based on our picosecond time-resolved photoluminescence studies we show that spontaneous radiative recombination is strongly influenced by excitonic effects, both in bulk GaN and in quantum wells. Particularly in quantum wells, localization of excitons plays an important role. We have studied the optical gain spectra in GaInN/GaN and GaN/AlGaN double heterostructures and quantum wells, grown by LP-MOVPE, using the stripe excitation method. Both room temperature and low temperature measurements were performed. Based on our results, we discuss the physical mechanism of optical gain in the nitrides as well as consequences for laser operation. We show that localization or, equivalently, the formation of quantum dot like structures, governs the optical gain mechanism in the nitrides.

Effects of Piezoelectric Fields in GaInN/GaN and GaN/AlGaN Heterostructures and Quantum Wells

1997 ◽  
Vol 482 ◽  
Author(s):  
Jin Seo Im ◽  
H. Kollmer ◽  
J. Off ◽  
A. Sohmer ◽  
F. Scholz ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantitative Model ◽  
Emission Lines ◽  
Strong Increase ◽  
Time Resolved ◽  
Double Heterostructures ◽  
Decay Times ◽  
Piezoelectric Fields ◽  
Experimental Findings ◽  
Time Resolved Photoluminescence

AbstractThe effects of piezoelectric fields on the static and dynamic optical properties of GaInN/GaN and GaN/AIGaN double heterostructures and single quantum wells are studied by time-resolved photoluminescence. We find a strong increase of the luminescence decay time of the dominating transition with well thickness by several orders of magnitude. For well thicknesses larger than about 5 nm, two emission lines with strongly differing decay times are observed, which are attributed to spatially direct and indirect transitions. Our experimental findings are consistently explained by a quantitative model based on the piezoelectric fields in strained wurtzite quantum wells.

Time-Resolved Photoluminescence Studies on AlGaN Double Heterostructures

2015 ◽  
Vol 33 (1) ◽  
pp. 76-81 ◽  
Author(s):  
Ponnusamy Arivazhagan ◽  
Eric Faulques ◽  
Fouad Bennis ◽  
Krishnan Baskar
Keyword(s):  
Time Resolved ◽  
Double Heterostructures ◽  
Photoluminescence Studies ◽  
Time Resolved Photoluminescence

Exciton dynamics in thick GaN MOVPE epilayers deposited on sapphire.

1997 ◽  
Vol 2 ◽  
Author(s):  
J. Allègre ◽  
P. Lefebvre ◽  
J. Camassel ◽  
B. Beaumont ◽  
Pierre Gibart
Keyword(s):  
Layer Thickness ◽  
Buffer Layers ◽  
Rate Equations ◽  
Time Resolved ◽  
Versus Layer ◽  
Level Model ◽  
Shallow Impurities ◽  
Aln Buffer ◽  
Time Resolved Photoluminescence

Time-resolved photoluminescence spectra have been recorded on three GaN epitaxial layers of thickness 2.5 μm, 7 μm and 16 μm, at various temperatures ranging from 8K to 300K. The layers were deposited by MOVPE on (0001) sapphire substrates with standard AlN buffer layers. To achieve good homogeneities, the growth was in-situ monitored by laser reflectometry. All GaN layers showed sharp excitonic peaks in cw PL and three excitonic contributions were seen by reflectivity. The recombination dynamics of excitons depends strongly upon the layer thickness. For the thinnest layer, exponential decays with τ ~ 35 ps have been measured for both XA and XB free excitons. For the thickest layer, the decay becomes biexponential with τ1 ~ 80 ps and τ2 ~ 250 ps. These values are preserved up to room temperature. By solving coupled rate equations in a four-level model, this evolution is interpreted in terms of the reduction of density of both shallow impurities and deep traps, versus layer thickness, roughly following a L−1 law.

ZnCdO/ZnMgO and ZnO/AlGaN Heterostructures for UV and Visible Light Emitters

2005 ◽  
Vol 892 ◽  
Author(s):  
Andrei Osinsky ◽  
Jianwei Dong ◽  
J. Q. Xie ◽  
B. Hertog ◽  
A. M. Dabiran ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Compositional Analysis ◽  
Optical Emission ◽  
Rf Plasma ◽  
Light Emitters ◽  
Time Resolved ◽  
Light Emitting ◽  
Spatially Resolved ◽  
Time Resolved Photoluminescence ◽  
Made In

AbstractThis paper reviews of some of the progress made in the development of ZnO-based light emitting diodes (LEDs). n-ZnO/p-AlGaN-based heterostructures have been successfully for the fabrication of UV emitting LEDs that have operated at temperatures up to 650K, suggesting an excitonic origin for the optical transitions. RF-plasma-assisted molecular beam epitaxy has been used to grow epitaxial CdxZn1-xO films on GaN/sapphire structure. These films have a single-crystal wurtzite structure as demonstrated by structural and compositional analysis. High quality CdxZn1-xO films were grown with up to x=0.78 mole fraction as determined by RBS and SIMS techniques. Optical emission ranging from purple (Cd0.05Zn0.95O) to yellow (Cd0.29Zn0.71O) was observed. Compositional fluctuations in a Cd0.16Zn0.84O films were not detected by spatially resolved CL measurements, although intensity fluctuation with features of ∼0.5 μm diameter were seen on the intensity maps. Time resolved photoluminescence shows multi-exponential decay with 21 psec. and 49±3 psec. lifetimes, suggesting that composition micro-fluctuations may be present in Cd0.16Zn0.84O film.

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