Study of Optical Gain in Thick GaN Epilayers by Variable Stripe Length Technique

2005 ◽  
Vol 866 ◽  
Author(s):  
G. Tamulaitis ◽  
J. Mickevic ◽  
M. Shur ◽  
Q. Fareed ◽  
R. Gaska
Keyword(s):  
Light Propagation ◽  
Chemical Vapor ◽  
High Gain ◽  
Gain Medium ◽  
Excitation Power ◽  
Organic Chemical ◽  
Excitation Power Density ◽  
One Dimensional ◽  
Light Amplification ◽  
Stripe Length

AbstractWe report on the gain study in high-quality thick GaN layers using the Variable Stripe Length (VSL) technique. The layers were grown by Migration Enhanced Metal Organic Chemical Vapor Deposition (MEMOCVDTM). The amplification of light was investigated for the propagation directions along the layer surface (perpendicular to the c-axis of the crystal) and perpendicular to the layer (along the c-axis) for the layers with thicknesses up to 11 νm. By fitting the experimental stripe length dependence of the edge luminescence with one-dimensional description of light amplification in medium with positive gain, peak gain coefficients of up to 7300 cm-1 were estimated in GaN at the excitation power density of 2 MW/cm2. We discuss limitations of the VSL technique due to the assumption of one-dimensional light propagation and strong influence of gain saturation in a high-gain medium. The contribution of new gain modes after saturation of the highest-gain modes was observed. The optical gains in GaN samples with different carrier lifetimes (obtained using time-resolved photoluminescence and light-induced transient grating techniques) were compared.

Surface Emission of InxGa1-x N/GaN Espaliers Grown by MOCVD under Different Optical Excitation

2012 ◽  
Vol 442 ◽  
pp. 393-397
Author(s):  
You Zhang Zhu ◽  
Yan Liu ◽  
Hong Xia Wang ◽  
Zhen Sun ◽  
Jin She Yuan
Keyword(s):  
Power Density ◽  
Chemical Vapor ◽  
Optical Excitation ◽  
Excitation Power ◽  
Organic Chemical ◽  
Light Sources ◽  
Excitation Power Density ◽  
Transmission Spectra ◽  
Surface Emission ◽  
The Difference

Photoluminescence properties of InGaN film grown on sapphire substrates by metal organic chemical vapor deposition(MOCVD) was experimentally Investigation. The x-ray diffraction(XRD), transmission spectra, PL spectrum were used. The result of XRD shows that the mole composition of In in the InGaN film is estimated be 0.2 approximately. The band gap of the sample is calculated to be 2.66eV. A clear oscillation from F-P cavity could be observed on transmission spectra. There are three main peaks from the surface emission InGaN espaliers being excited on different light sources and different excitation power density. which can be explained the broad PL come from the difference of In composition modulated by was modulated due to F-P cavity arising from surface of sample. . It is found that there is some relationship between the position of the peaks in the PL spectra, the wavelength and intensity of power density and the F-P cavity.PACS: 73.61.

scholarly journals Raman Spectroscopic Characterizations of Self-Catalyzed InP/InAs/InP One-Dimensional Nanostructures on InP(111)B Substrate using a Simple Substrate-Tilting Method

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Jeung Hun Park ◽  
Choong-Heui Chung
Keyword(s):  
Low Frequency ◽  
Chemical Vapor ◽  
Excitation Power ◽  
Organic Chemical ◽  
Core Shell ◽  
Vibration Modes ◽  
Strong Suppression ◽  
One Dimensional ◽  
Frequency Branch ◽  
One Dimensional Nanostructures

AbstractWe report optical phonon vibration modes in ensembles of self-catalyzed InP/InAs/InP multi core-shell one-dimensional nanostructures (nanopillars and nanocones) grown on InP(111)B substrates using liquid indium droplets as a catalyst via metal-organic chemical vapor deposition. We characterized the Raman vibration modes of InAs E1(TO), InAs A1(TO), InAs E1(LO), InP E1(TO), InP A1(LO), and InP E1(LO) from the ensemble of as-grown nanostructures. We also identified second-order Raman vibration modes, associated with InP E1(2TO), E1(LO+TO), and E1(2LO), in the InP/InAs/InP core-shell nanopillars and nanocones. Raman spectra of InP/InAs/InP nanopillars showed redshift and broadening of LO modes at low-frequency branches of InAs and InP. Due to the polar nature in groups III–V nanowires, we observed strong frequency splitting between InAs E1(TO) and InAs A1(LO) in InP/InAs/InP nanocones. The Raman resonance intensities of InP and InAs LO modes are found to be changed linearly with an excitation power. By tilting the substrate relative to the incoming laser beam, we observed strong suppression of low-frequency branch of InP and InAs LO phonon vibrations from InP/InAs/InP nanocones. The integrated intensity ratio of InP E1(TO)/E1(LO) for both nanostructures is almost constant at 0-degree tilt, but the ratio of the nanocones is dramatically increased at 30-degree tilt. Our results suggest that Raman spectroscopy characterization with a simple substrate tilting method can provide new insights into non-destructive characterization of the shape, structure, and composition of the as-grown nanostructures for the wafer-scale growth and integration processing of groups III–V semiconducting hetero-nanostructures into nanoelectronics and photonics applications.

UV Emission Mechanisms in Quaternary AlInGaN Epilayers and Multiple Quantum Wells

2002 ◽  
Vol 722 ◽  
Author(s):  
Mee-Yi Ryu ◽  
C. Q. Chen ◽  
E. Kuokstis ◽  
J. W. Yang ◽  
G. Simin ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Light Emitting Diode ◽  
Chemical Vapor ◽  
Excitation Power ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Excitation Power Density ◽  
Light Emitting ◽  
Uv Emission ◽  
Alloy Disorder

AbstractWe present the results on investigation and analysis of photoluminescence (PL) dynamics of quaternary AlInGaN epilayers and AlInGaN/AlInGaN multiple quantum wells (MQWs) grown by a novel pulsed metalorganic chemical vapor deposition (PMOCVD). The emission peaks in both AlInGaN epilayers and MQWs show a blueshift with increasing excitation power density. The PL emission of quaternary samples is attributed to recombination of carriers/excitons localized at band-tail states. The PL decay time increases with decreasing emission photon energy, which is a characteristic of localized carrier/exciton recombination due to alloy disorder. The obtained properties of AlInGaN materials grown by a PMOCVD are similar to those of InGaN. This indicates that the AlInGaN system is promising for ultraviolet applications such as the InGaN system for blue light emitting diode and laser diode applications.

Growth and Characterization of In-Based Nitride Compounds and their Double Heterostructures

1997 ◽  
Vol 468 ◽  
Author(s):  
V. A. Joshkin ◽  
J. C Roberts ◽  
E. L. Piner ◽  
M. K. Behbehani ◽  
F. G. McIntosh ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Growth Conditions ◽  
Excitation Power ◽  
Excitation Power Density ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
Recombination Lifetime ◽  
Pl Spectra ◽  
Double Heterostructures

ABSTRACTWe report on the growth and characterization of InGaN bulk films and AlGaN/InGaN/AlGaN double heterostructures (DHs). Good quality bulk InGaN films have been grown by metalorganic chemical vapor deposition (MOCVD) with up to 40% InN as characterized by x-ray diffraction. The effect of hydrogen in the growth ambient on the lnN% incorporation in the InGaN films is presented. Photoluminescence (PL) spectra of AlGaN/InGaN/AlGaN DHs exhibit emission wavelengths from the violet through yellow depending on the growth conditions of the active InGaN layer. The PL spectra are fairly broad both at room temperature and 20 K, and could be a result of native defects or impurity related transitions. We also observed a linear dependence between the PL intensity and excitation power density in the 0.001 W/cm2 to 10 MW/cm2 range. Time resolved PL of one of these DHs suggest a recombination lifetime on the order of 520 ps.

CRYSTALLINE PHASE SEPARATION OF InGaN LAYER MATERIALS PREPARED BY METALORGANIC CHEMICAL VAPOR DEPOSITION

2002 ◽  
Vol 16 (01n02) ◽  
pp. 268-274
Author(s):  
ZHE CHUAN FENG ◽  
TZUEN RONG YANG ◽  
RONG LIU ◽  
ANDREW THYE SHEN WEE
Keyword(s):  
Chemical Vapor Deposition ◽  
Phase Separation ◽  
Vapor Deposition ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Vapor ◽  
Excitation Power ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
Uniform Distributions ◽  
Metal Organic

Zn -doped InGaN thin films were epitaxied on the top of 1-2 micron thick GaN grown on sapphire by metal organic chemical vapor deposition, and studied by a combination of high resolution X-ray diffraction (HR-XRD), micro-photoluminescence (PL) and secondary ion mass spectrometry (SIMS). HRXRD exhibits a GaN band and a single band from InGaN for samples without phase separation, but two or more InGaN bands corresponding to different x(In) for samples with phase separation. PL emissions from InGaN spread over a wider energy ranges and were modulated by the interference effects. Excitation power dependence measurements reveal 2-sets of PL emissions for samples with phase separation, but only 1-set for samples without phase separation. SIMS data showed that phase separated InGaN:Zn films possess a high Zn concentration near the InGaN-GaN interface and non-uniform distributions of In and Zn contents, which are in contrast with data from InGaN:Zn films with no In -phase separation. These interesting results are correlated to the growth process and microstructural properties.

ZnO nanostructures epitaxially grown on ZnO seeded Si (100) substrates by chemical vapor deposition

2009 ◽  
Vol 1178 ◽  
Author(s):  
Zhuo Chen ◽  
Tom Salagaj ◽  
Christopher Jensen ◽  
Kai Shum
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Excitation Power ◽  
Zno Thin Films ◽  
Excitation Power Density ◽  
Zno Nanostructures ◽  
Cvd Method ◽  
Nanowire Networks ◽  
Scanning Electron

AbstractZnO nanostructures such as nanowire-networks and vertical nanorods were epitaxially grown on pre-seeded Si (100) substrates by chemical vapor deposition (CVD) method with a solid source. Crystalline ZnO seeds were prepared and controlled by the rapid thermal annealing (RTA) treatment of e-beam deposited amorphous ZnO thin films. Both epitaxially grown ZnO nanostructures and pre-deposited ZnO seeds were characterized by scanning electron microscopy (SEM), and photoluminescence (PL) spectroscopy. Excellent optical characteristics of these nanostructures such as PL line width, linearity of PL intensity as a function of excitation power density were obtained.

scholarly journals Optical Properties of InGaN/GaN QW with the Same Well-Plus-Barrier Thickness

Crystals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 114
Author(s):  
Huan Xu ◽  
Xin Hou ◽  
Lan Chen ◽  
Yang Mei ◽  
Baoping Zhang
Keyword(s):  
Optical Properties ◽  
Chemical Vapor ◽  
Excitation Power ◽  
Organic Chemical ◽  
Barrier Thickness ◽  
Radiation Process ◽  
Peak Energy ◽  
Two Samples ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

Optical properties of wurtzite violet InGaN/GaN quantum well (QW) structures, with the same well-plus-barrier thickness, grown by metal-organic chemical vapor deposition (MOCVD) on c-plane sapphire substrates, were investigated using temperature-dependent photoluminescence (TDPL) and excitation-power-dependent photoluminescence (PDPL). Two samples were compared: one had a thicker well (InGaN/GaN 3/5 nm); the other had a thicker barrier (InGaN/GaN 2/6 nm). It was found that the GaN barrier thickness in the InGaN/GaN MQWs plays an important role in determining the optical characteristics of the MQWs. The peak energy of the two samples varied with temperature in an S-shape. The thicker-barrier sample had a higher turning point from blueshift to redshift, indicating a stronger localization effect. From the Arrhenius plot of the normalized integrated PL intensity, it was found that the activation energy of the nonradiative process also increased with a thicker barrier thickness. The radiation recombination process was dominated in the sample of the thicker barrier, while the non-radiation process cannot be negligible in the sample of the thicker well.

Excitation-power mediated optical hysteresis behavior in a single one-dimensional upconverting microcrystal

2018 ◽  
Vol 6 (30) ◽  
pp. 8011-8019 ◽  
Author(s):  
Dangli Gao ◽  
Xiangyu Zhang ◽  
Qing Pang ◽  
Jin Zhao ◽  
Guoqing Xiao ◽  
...  
Keyword(s):  
Power Density ◽  
Luminescence Intensity ◽  
Excitation Power ◽  
Excitation Power Density ◽  
One Dimensional ◽  
Hysteresis Behavior

An interesting OHB of luminescence intensity was observed when we varied the excitation power density back and forth.

Structural and electronic properties of defects in semiconductors

1995 ◽  
Vol 53 ◽  
pp. 4-5
Author(s):  
J.L. Batstone
Keyword(s):  
Semiconductor Device ◽  
Chemical Vapor ◽  
Misfit Strain ◽  
Organic Chemical ◽  
Extended Defects ◽  
Transmission Electron ◽  
Semiconductor Thin Films ◽  
Wide Range ◽  
Metal Organic ◽  
Film Substrate

The development of growth techniques such as metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy during the last fifteen years has resulted in the growth of high quality epitaxial semiconductor thin films for the semiconductor device industry. The III-V and II-VI semiconductors exhibit a wide range of fundamental band gap energies, enabling the fabrication of sophisticated optoelectronic devices such as lasers and electroluminescent displays. However, the radiative efficiency of such devices is strongly affected by the presence of optically and electrically active defects within the epitaxial layer; thus an understanding of factors influencing the defect densities is required.Extended defects such as dislocations, twins, stacking faults and grain boundaries can occur during epitaxial growth to relieve the misfit strain that builds up. Such defects can nucleate either at surfaces or thin film/substrate interfaces and the growth and nucleation events can be determined by in situ transmission electron microscopy (TEM).

{10} edge dislocations in YSZ films grown on (100)MgO by PLD

1994 ◽  
Vol 52 ◽  
pp. 530-531
Author(s):  
Jason R. Heffelfinger ◽  
C. Barry Carter
Keyword(s):  
Thin Films ◽  
Semiconductor Lasers ◽  
Vapor Deposition ◽  
Substrate Surface ◽  
Laser System ◽  
Average Energy ◽  
Target Material ◽  
Chemical Vapor ◽  
Buffer Layers ◽  
Organic Chemical

Yttria-stabilized zirconia (YSZ) is currently used in a variety of applications including oxygen sensors, fuel cells, coatings for semiconductor lasers, and buffer layers for high-temperature superconducting films. Thin films of YSZ have been grown by metal-organic chemical vapor deposition, electrochemical vapor deposition, pulse-laser deposition (PLD), electron-beam evaporation, and sputtering. In this investigation, PLD was used to grow thin films of YSZ on (100) MgO substrates. This system proves to be an interesting example of relationships between interfaces and extrinsic dislocations in thin films of YSZ.In this experiment, a freshly cleaved (100) MgO substrate surface was prepared for deposition by cleaving a lmm-thick slice from a single-crystal MgO cube. The YSZ target material which contained 10mol% yttria was prepared from powders and sintered to 85% of theoretical density. The laser system used for the depositions was a Lambda Physik 210i excimer laser operating with KrF (λ=248nm, 1Hz repetition rate, average energy per pulse of 100mJ).

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