In Situ Diagnostics of Nanomaterial Synthesis by Laser Ablation: Time-resolved Photoluminescence Spectra and Imaging of Gas-Suspended Nanoparticles Deposited for Thin Films

1998 ◽  
Vol 536 ◽  
Author(s):  
D. B. Geohegan ◽  
A. A. Puretzky ◽  
A. Meldrum ◽  
G. Duscher ◽  
S. J. Pennycook
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Rayleigh Scattering ◽  
Silicon Nanoparticles ◽  
Time Resolved ◽  
Nanomaterial Synthesis ◽  
Z Contrast ◽  
Time Resolved Photoluminescence ◽  
Suspended Nanoparticles

AbstractThe dynamics of nanoparticle formation by laser ablation into background gases are revealed by gated-ICCD photography of photoluminescence (PL) and Rayleigh-scattering (RS) from gas-suspended nanoparticles. These techniques, along with gated-spectroscopy of PL from isolated, gassuspended nanoparticles, permit fundamental investigations of nanomaterial growth, doping, and luminescence properties prior to deposition for thin films. Using the time-resolved diagnostics, particles unambiguously formed in the gas phase were collected on TEM grids. Silicon nanoparticles, 1-10 nm in diameter, were deposited following laser ablation into 1-10 TorrAror He. Three in situ PL bands (1.8, 2.6, 3.2 eV) similar to oxidized porous silicon were measured, but with a pronounced vibronic structure. Structureless photoluminescence bands were reproduced in the films (2.1, 2.7, 3.2 eV) only after standared annealing. The ablation of metal zinc into Ar/02 is also reported for the preparation of < 10 nm diameter hexagonal zincite nanocrystals, The particles were analyzed by bright field and Z-contrast TEM and high resolution EELS.

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.

scholarly journals Defects characterization in thin films photovoltaics materials by correlated high-frequency modulated and time resolved photoluminescence: An application to Cu(In,Ga)Se2

2019 ◽  
Vol 669 ◽  
pp. 520-524
Author(s):  
Baptiste Bérenguier ◽  
Nicolas Barreau ◽  
Alexandre Jaffre ◽  
Daniel Ory ◽  
Jean-François Guillemoles ◽  
...  
Keyword(s):  
Thin Films ◽  
High Frequency ◽  
Time Resolved ◽  
Time Resolved Photoluminescence

Electric-field-induced lattice distortion in epitaxial BiFeO3 thin films as determined by in situ time-resolved x-ray diffraction

2017 ◽  
Vol 111 (8) ◽  
pp. 082907 ◽  
Author(s):  
Seiji Nakashima ◽  
Osami Sakata ◽  
Hiroshi Funakubo ◽  
Takao Shimizu ◽  
Daichi Ichinose ◽  
...  
Keyword(s):  
Thin Films ◽  
Electric Field ◽  
Lattice Distortion ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Bifeo3 Thin Films

In-situ investigation of laser ablation of thin films

1995 ◽  
Vol 254 (1-2) ◽  
pp. 139-146 ◽  
Author(s):  
E. Matthias ◽  
J. Siegel ◽  
S. Petzoldt ◽  
M. Reichling ◽  
H. Skurk ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
In Situ Investigation

In-situ and multilayer laser ablation deposition of Pb2Sr2Y0.5Ca0.5Cu3O8+δ thin films

1992 ◽  
Vol 54 ◽  
pp. 166-170 ◽  
Author(s):  
S.H.H. Naqvi ◽  
F. Beech ◽  
I.W. Boyd
Keyword(s):  
Thin Films ◽  
Laser Ablation

Time-resolved photoluminescence study of organic polysilane–silica hybrid thin films

2002 ◽  
Vol 299-302 ◽  
pp. 1052-1056 ◽  
Author(s):  
A. Kobayashi ◽  
H. Naito ◽  
Y. Matsuura ◽  
K. Matsukawa ◽  
S. Nihonyanagi ◽  
...  
Keyword(s):  
Thin Films ◽  
Time Resolved ◽  
Photoluminescence Study ◽  
Hybrid Thin Films ◽  
Time Resolved Photoluminescence ◽  
Silica Hybrid

Optimization of KrF laser ablation parameters for in-situ growth of Y1Ba2Cu3O7−δ thin films

1992 ◽  
Vol 196 (3-4) ◽  
pp. 264-270 ◽  
Author(s):  
R. Pinto ◽  
S.P. Pai ◽  
C.P. D'Souza ◽  
L.C. Gupta ◽  
R. Vijayaraghavan ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
In Situ Growth ◽  
Krf Laser

Electrochemistry of Thin Films with In Situ/Operando Grazing Incidence X‐Ray Scattering: Bypassing Electrolyte Scattering for High Fidelity Time Resolved Studies

Small ◽  
2021 ◽  
pp. 2103213
Author(s):  
Bryan D. Paulsen ◽  
Alexander Giovannitti ◽  
Ruiheng Wu ◽  
Joseph Strzalka ◽  
Qingteng Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Grazing Incidence ◽  
High Fidelity ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

scholarly journals Preparation of the group III nitride thin films AlN, GaN, InN by direct and reactive pulsed laser ablation

2001 ◽  
Vol 3 (3) ◽  
pp. 111-121 ◽  
Author(s):  
Aldo Mele ◽  
Anna Giardini ◽  
Tonia M. Di Palma ◽  
Chiara Flamini ◽  
Hideo Okabe ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Group Iii Nitrides ◽  
X Ray Diffraction ◽  
Subsequent Reaction ◽  
X Ray ◽  
Group Iii ◽  
Emission Spectroscopic Analysis ◽  
Group Iii Nitride

The methods of preparation of the group III nitrides AlN, GaN, and InN by laser ablation (i.e. laser sputtering), is here reviewed including studies on their properties. The technique, concerns direct ablation of nitride solid targets by laser to produce a plume which is collected on a substrate. Alternatively nitride deposition is obtained as a result of laser ablation of the metal and subsequent reaction in anNH3atmosphere. Optical multichannel emission spectroscopic analysis, and time of flight (TOF) mass spectrometry have been applied forin situidentification of deposition precursors in the plume moving from the target. Epitaxial AlN, GaN, and InN thin films on various substrates have been grown. X-ray diffraction, scanning electron microscopy, have been used to characterise thin films deposited by these methods.

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