scholarly journals Localized overheating on aluminum metafilms mediated by surface plasmons

2021 ◽  
Vol 67 (5 Sep-Oct) ◽  
Author(s):  
David Eduardo Martínez Lara ◽  
Ricardo González Campuzano ◽  
José Luis Benítez Benítez ◽  
Doroteo Mendoza López
Keyword(s):  
Electrical Resistivity ◽  
Surface Plasmons ◽  
Wavelength Range ◽  
Radiative Decay ◽  
Incident Radiation ◽  
Geometric Parameters ◽  
Temperature Measurements ◽  
Hot Electrons ◽  
Aluminum Films ◽  
Thin Aluminum

We studied the increase in temperature of systems formed by thin aluminum films deposited on texturized substrates which we denominated aluminum metafilms. By varying the geometric parameters of the metafilms, surface plasmons in the wavelength range of ~420-770 nm were excited. Temperature measurements as a function of the intensity of incident radiation in the interval from 0-to 4X10^18 (photons/s cm^2) using wavelengths of 445, 532 and 650 nm, showed temperature increases up to ~200 K, these attributed to metafilm morphology and hot electrons result of the non-radiative decay of the surface plasmons. Also increases up to 2.3X10^(-4) Ohm cm  in electrical resistivity were recorded when the metafilms were radiated for times of ~1 s; when the exposure times were greater than ~4 s, irreversibly changes in the morphology of the samples were observed.

Time-Resolved, Laser-Induced Phase Transformation in Aluminum

1984 ◽  
Vol 35 ◽  
Author(s):  
S. Williamson ◽  
G. Mourou ◽  
J.C.M. Li
Keyword(s):  
Point Defect ◽  
Long Range ◽  
Rapid Heating ◽  
Range Order ◽  
Nucleation Theory ◽  
Long Range Order ◽  
Time Resolved ◽  
Aluminum Films ◽  
Thin Aluminum ◽  
Initial Nucleus

ABSTRACTThe technique of picosecond electron diffraction is used to time resolve the laser-induced melting of thin aluminum films. It is observed that under rapid heating conditions, the long range order of the lattice subsists for lattice temperatures well above the equilibrium point, indicative of superheating. This superheating can be verified by directly measuring the lattice temperature. The collapse time of the long range order is measured and found to vary from 20 ps to several nanoseconds according to the degree of superheating. Two interpretations of the delayed melting are offered, based on the conventional nucleation and point defect theories. While the nucleation theory provides an initial nucleus size and concentration for melting to occur, the point defect theory offers a possible explanation for how the nuclei are originally formed.

scholarly journals Superlayer Residual Stress Effect on the Indentation Adhesion Measurements

1999 ◽  
Vol 594 ◽  
Author(s):  
Alex A. Volinsky ◽  
Neville R. Moody ◽  
William W. Gerberich
Keyword(s):  
Residual Stress ◽  
Sputter Deposition ◽  
Work Of Adhesion ◽  
Stress Effect ◽  
Aluminum Films ◽  
Nanoindentation Testing ◽  
Deposition Parameters ◽  
Thin Aluminum ◽  
Residual Stress Effect ◽  
Sputter Deposited

AbstractThe practical work of adhesion has been measured in thin aluminum films as a function of film thickness and residual stress. These films were sputter deposited onto thermally oxidized silicon wafers followed by sputter deposition of a one micron thick W superlayer. The superlayer deposition parameters were controlled to produce either a compressive residual stress of 1 GPa or a tensile residual stress of 100 MPa. Nanoindentation testing was then used to induce delamination and a mechanics based model for circular blister formation was used to determine practical works of adhesion. The resulting measured works of adhesion for all films between 100 nm and 1 μm thick was 30 J/m2 regardless of superlayer stress. However, films with the compressively stressed superlayers produced larger blisters than films with tensile stressed superlayers. In addition, these films were susceptible to radial cracking producing a high variability in average adhesion values.

Investigations on the Aluminum/Para-Hexaphenyl Interface in Light Emitting Devices

1997 ◽  
Vol 488 ◽  
Author(s):  
N. Koch ◽  
L.-M. Yu ◽  
J.-L. Guyaux ◽  
Y. Morciaux ◽  
G. Leising ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Active Material ◽  
Direct Interaction ◽  
Metal Electrode ◽  
Insulating Layer ◽  
Aluminum Films ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Thin Aluminum

AbstractBlue light emitting devices (LED) with para-hexaphenyl (PHP) as the active material and aluminum as cathode exhibit very high quantum efficiencies. To further optimize device performance it is crucial to understand the physical properties of the involved interfaces. We have performed Rutherford-Backscattering experiments on actual devices to show the importance of oxygen in the interface formation at the cathode as this leads to the formation of a layer of AlxOy between PHP and aluminum. In devices, where the organic film is exposed to air before the metal electrode is evaporated, an insulating layer on the metal-side therefore is inherent. It has been shown that the introduction of an intermediate layer between active material and electrodes results in a higher quantum efficiency of the LED, the most common concepts being charge-transport-layers, or insulators on the other hand. Our results underline the need for a better control of the LED processing. Ultraviolet- and X-ray photoelectron spectroscopy in situ growth studies of thin aluminum films on PHP have been made to reveal the change in the electronic structure of the active medium in a LED in the absence of oxygen. Also the direct interaction of oxygen with this organic material is investigated by photoelectron spectroscopy.

Properties of Very Thin Aluminum Films

1971 ◽  
Vol 42 (1) ◽  
pp. 51-53 ◽  
Author(s):  
R. Meservey ◽  
P. M. Tedrow
Keyword(s):  
Aluminum Films ◽  
Thin Aluminum

Detonation Chemistry Of Glycidyl Azide Polymer

1995 ◽  
Vol 418 ◽  
Author(s):  
Ping Ling ◽  
Jill Sakata ◽  
Charles A. Wight
Keyword(s):  
Laser Fluence ◽  
Molecular Nitrogen ◽  
Initial Step ◽  
Laser Vaporization ◽  
Initial Reaction ◽  
Glycidyl Azide Polymer ◽  
Aluminum Films ◽  
Thin Aluminum ◽  
Before And After ◽  
Glycidyl Azide

AbstractThe initial step of chemical reaction initiated by laser-generated shock waves has been observed in glycidyl azide polymer (GAP) in condensed phase. Shocks are generated by pulsed laser vaporization of thin aluminum films and launched into adjacent films of GAP at 77 K. Comparison of FIIR spectra obtained before and after shock passage shows that initial reaction involves elimination of molecular nitrogen from the azide functional groups of the polymer. The shock arrival time has been measured by a velocity interferometer as a function of thickness of GAP and laser fluence. The shock pressure has been calculated by using a universal liquid state Hugoniot. A simple model is proposed to calculate shock velocity and pressure as a function of laser fluence. The results are in agreement with experimental data.

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