Growth of ZnSe Epitaxial Layers and ZnSe/ZnS Superlattices by Pulsed Laser Deposition

1992 ◽  
Vol 285 ◽  
Author(s):  
Y. Rajakarunanayake ◽  
Y. Luo ◽  
B. T. Adkins ◽  
A. Compaan
Keyword(s):  
Pulsed Laser Deposition ◽  
Free Exciton ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Ultra High Vacuum ◽  
Laser Deposition ◽  
Epitaxial Layers ◽  
Growth Technique ◽  
Light Emitter ◽  
Strained Layer Superlattices

ABSTRACTWe report the successful growth of ZnSe and ZnSe/ZnS superlattices on GaAs by pulsed laser deposition. An XeCl excimer laser operated at 308 nm was used to ablate/evaporate Il-VI bulk targets in an ultra high vacuum enclosure. For typical growth temperatures in the range 350°–450°C we obtained epitaxial layers with excellent optical properties. The laser power and fluence were varied to produce growth rates in the range 0.1–1 Å/pulse. The photoluminescence of the pulsed laser deposited ZnSe layers showed dominant bound and free exciton features. The superlattice samples showed large blue shifts (∼400 meV) in the photoluminescence as the layer thicknesses were varied. These results are consistent with strong quantum confinement of the heavy holes in the ZnSe layers (valence band offset for ZnSe/ZnS ∼ 850±100 meV), while the electrons are not confined to either layer because of very small conduction band offsets Strong exciton photoluminescence exhibited by our samples indicates that pulsed laser deposition is a promising growth technique for the fabrication of iI-VI epitaxial layers and strained layer superlattices for visible light emitter applications.

Epitaxial Growth of ZnTe and ZnSe on GaAs by Pulsed Laser Deposition

1992 ◽  
Vol 268 ◽  
Author(s):  
Y. Rajakarunanayake ◽  
Y. Luo ◽  
A. Aydinli ◽  
N Lavalle ◽  
A. Compaan
Keyword(s):  
Pulsed Laser Deposition ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Ultra High Vacuum ◽  
Laser Deposition ◽  
Near Band Edge ◽  
Epitaxial Layers ◽  
High Crystalline Quality ◽  
Growth Technique ◽  
Edge Features

ABSTRACTWe report the successful growth of ZnTe and ZnSe epitaxial layers on GaAs by pulsed laser deposition. A frequency doubled Nd:YAG laser was used to ablate/evaporate II-VI bulk targets and pressed powder targets in an ultra high vacuum enclosure. For typical growth temperatures in the range 200°-400°C x-ray analysis of the layers revealed sharp <100> peaks with no evidence of growth in other orientations. Polarization dependent Raman spectroscopy was also used to further characterize the epitaxial layers, by verifying the selection rules for backscattering from <100> oriented films. The low temperature photoluminescence spectra show distinct near-band-edge features indicating high crystalline quality. The photoluminescence of the films grown from bulk targets was superior to that of films grown from pressed powder targets, indicating that the use of high purity bulk targets is critical. Our results indicate that pulsed laser deposition is a promising new growth technique for the fabrication of II-VI epitaxial layers with unique advantages.

scholarly journals Annealing Condition Effects on the Structural Properties of FePt Nanoparticles Embedded in MgO via Pulsed Laser Deposition

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 131
Author(s):  
Tingting Xiao ◽  
Qi Yang ◽  
Jian Yu ◽  
Zhengwei Xiong ◽  
Weidong Wu
Keyword(s):  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Annealing Process ◽  
Ultra High Vacuum ◽  
Laser Deposition ◽  
Fept Nanoparticles ◽  
Annealing Conditions ◽  
Vacuum Atmosphere

FePt nanoparticles (NPs) were embedded into a single-crystal MgO host by pulsed laser deposition (PLD). It was found that its phase, microstructures and physical properties were strongly dependent on annealing conditions. Annealing induced a remarkable morphology variation in order to decrease its total free energy. H2/Ar (95% Ar + 5% H2) significantly improved the L10 ordering of FePt NPs, making magnetic coercivity reach 37 KOe at room temperature. However, the samples annealing at H2/Ar, O2, and vacuum all showed the presence of iron oxide even with the coverage of MgO. MgO matrix could restrain the particles’ coalescence effectively but can hardly avoid the oxidation of Fe since it is extremely sensitive to oxygen under the high-temperature annealing process. This study demonstrated that it is essential to anneal FePt in a high-purity reducing or ultra-high vacuum atmosphere in order to eliminate the influence of oxygen.

Pulsed Laser Deposition and In Situ Scanning Tunneling Microscopy of Pd clusters supported on alumina

2011 ◽  
Vol 1351 ◽  
Author(s):  
C.S. Casari ◽  
S. Foglio ◽  
M. Corbetta ◽  
M. Passoni ◽  
C.E. Bottani ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Pulsed Laser Deposition ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Ultra High Vacuum ◽  
Laser Deposition ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Pd Clusters

ABSTRACTWith the aim of addressing the material gap issue between model and real systems in heterogeneous catalysis, we exploited Pulsed Laser Deposition (PLD) to produce Pd clusters supported on ultrathin alumina films (Pd/Al2O3/NiAl(001) and Pd/Al2O3-x/HOPG). The structural properties have been investigated by in situ Scanning Tunneling Microscopy (STM) in ultra high vacuum (UHV). At first, Pd clusters were deposited by evaporation and by PLD on Al2O3 surfaces grown by thermal oxidation of NiAl(001). The system shows thermal stability up to 650 K. By PLD we deposited Pd clusters with a good size control obtained by varying the background gas pressure and the target-to-substrate distance. We then realized aPd/Al2O3-x/HOPG system where both Pd clusters and the alumina film are produced by PLD showing that, by exploiting the same deposition technique, it is possible to synthesize both a model system addressable by in situ STM and a thick film (∼100 μm) closer to realistic systems.

Structural and Electrical Characterization of Highly Tetrahedral-Coordinated Diamond-Like Carbon Films Grown by Pulsed-Laser Deposition

1994 ◽  
Vol 349 ◽  
Author(s):  
M. P. Siegal ◽  
T. A. Friedmann ◽  
S. R. Kurtz ◽  
D. R. Tallant ◽  
R. L. Simpson ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Growth Parameters ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Electrical Characterization ◽  
Carbon Films ◽  
Laser Deposition ◽  
High Resistivity ◽  
Low Frequencies ◽  
Carbon Carbon Bond

ABSTRACTHighly tetrahedral-coordinated-amorphous-carbon (a-tC) films deposited by pulsed-laser deposition (PLD) on silicon substrates are studied. These films are grown at room-temperatures in a high-vacuum ambient. a-tC films grown in this manner have demonstrated stability to temperatures in excess of T = 1000°C, more than sufficient for any post-processing treatment or application. Film surfaces are optically smooth as determined both visually and by atomic-force microscopy. PLD growth parameters can be controlled to produce films with a range of sp2 - sp3 carbon-carbon bond ratios. Films with the highest yield of sp3 C-C bonds have high resistivity, with a dielectric permittivity constant s σ 4, measured capacitively at low frequencies (1 – 100 kHz). These a-tC films are p-type semiconductors as grown. Schottky barrier diode structures have been fabricated.

Highly crystalline 5H-polytype of sp3-bonded boron nitride prepared by plasma-packets-assisted pulsed-laser deposition: An ultraviolet light emitter at 225 nm

2002 ◽  
Vol 81 (24) ◽  
pp. 4547-4549 ◽  
Author(s):  
Shojiro Komatsu ◽  
Keiji Kurashima ◽  
Hisao Kanda ◽  
Katsuyuki Okada ◽  
Mamoru Mitomo ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Pulsed Laser Deposition ◽  
Ultraviolet Light ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Light Emitter

Fabricating Two-Dimensional Metal Nanocrystal Arrays Using Pulsed-Laser Deposition and Focused Ion-Beam Technologies

2000 ◽  
Vol 636 ◽  
Author(s):  
Richard F. Haglund ◽  
Robert A. Weller ◽  
Cynthia E. Heiner ◽  
Matthew D. McMahon ◽  
Robert H. Magruder ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Silicon Surfaces ◽  
Silver Nanoclusters ◽  
Laser Evaporation ◽  
Si Substrates

AbstractWe describe recent experiments in which we attempted the initial steps for fabricating twodimensional arrays of metal nanocrystals. We use a commercial pulsed-laser deposition system in concert with a focused ion beam to attempt control over both lateral and vertical dimensions at the nanometer length scale. In our experiments, regular arrays of holes typically 80 nm in diameter were drilled in Si substrates using the focused ion beam. Silver atoms were then deposited onto these substrates by pulsed laser evaporation from a metallic target in high vacuum. Under certain conditions of substrate temperature, laser pulse repetition rate, and fluence, small silver nanoclusters form preferentially around the structures previously etched in the silicon surfaces by the focused ion beam.

Pulsed Laser Deposition of Poly(Tetrafluoroethylene) Films

1995 ◽  
Vol 397 ◽  
Author(s):  
D.L. Kjendal ◽  
Ashok Kumar ◽  
R.B. Inturi ◽  
J. A. Barnard
Keyword(s):  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
High Vacuum ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Deposition Technique ◽  
Nano Indentation ◽  
Corning Glass ◽  
Deposition Parameters ◽  
Compositional Properties

ABSTRACTThin films of poly(tetrafluoroethylene) have been deposited on amorphous (7059 Corning Glass) and silicon(l00) substrates at various temperatures by the Pulsed Laser Deposition technique. The deposition was carried out at high vacuum (˜10-6 torr)at temperatures ranging from room temperature to 350°C. The mechanical properties of these films at the varying process temperatures have been evaluated by nano-indentation techniques and compositional properties of the films have been characterized by Fourier Transform Infrared spectroscopy. The deposition parameters have been optimized in order to produce good quality films.

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