Laser thin films with very high damage threshold

2005 ◽  
Author(s):  
Jianda Shao ◽  
Zhengxiu Fan
Keyword(s):  
Thin Films ◽  
Damage Threshold ◽  
Very High

The observation of nano-voids in Au thin films

1987 ◽  
Vol 45 ◽  
pp. 366-367
Author(s):  
William Krakow
Keyword(s):  
Thin Films ◽  
Melting Point ◽  
Present Author ◽  
Stacking Faults ◽  
Damage Threshold ◽  
Ionic Species ◽  
Rare Gases ◽  
Chain Defects ◽  
Vacancy Chains ◽  
Au Thin Films

It has long been known that defects such as stacking faults and voids can be quenched from various alloyed metals heated to near their melting point. Today it is common practice to irradiate samples with various ionic species of rare gases which also form voids containing solidified phases of the same atomic species, e.g. ref. 3. Equivalently, electron irradiation has been used to produce damage events, e.g. ref. 4. Generally all of the above mentioned studies have relied on diffraction contrast to observe the defects produced down to a dimension of perhaps 10 to 20Å. Also all these studies have used ions or electrons which exceeded the damage threshold for knockon events. In the case of higher resolution studies the present author has identified vacancy and interstitial type chain defects in ion irradiated Si and was able to identify both di-interstitial and di-vacancy chains running through the foil.

scholarly journals Measurement of Electrical Properties of Superconducting YBCO Thin Films in the VHF Range

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3360
Author(s):  
Yakir Dahan ◽  
Eldad Holdengreber ◽  
Elichai Glassner ◽  
Oz Sorkin ◽  
Shmuel E. Schacham ◽  
...  
Keyword(s):  
Thin Films ◽  
Theoretical Model ◽  
Quality Factor ◽  
High Frequency ◽  
Unit Length ◽  
Superconducting Thin Films ◽  
Electrical Parameters ◽  
Very High Frequency ◽  
Production Constraints ◽  
Very High

A new measurement technique of electrical parameters of superconducting thin films at the Very High Frequency (VHF) range is described, based on resonators with microstrip (MS) structures. The design of an optimal resonator was achieved, based on a thorough theoretical analysis, which is required for derivation of the exact configuration of the MS. A theoretical model is presented, from which an expression for the attenuation of a MS line can be derived. Accordingly, simulations were performed, and an optimal resonator for the VHF range was designed and implemented. Production constraints of YBa2Cu3O7 (YBCO) limited the diameter of the sapphire substrate to 3″. Therefore, a meander configuration was formed to fit the long λ/4 MS line on the wafer. By measuring the complex input reflection coefficients of a λ/4 resonator, we extracted the quality factor, which is mainly affected by the dielectric and conductor attenuations. The experimental results are well fitted by the theoretical model. The dielectric attenuation was calculated using the quasi-static analysis of the MS line. An identical copper resonator was produced and measured to compare the properties of the YBCO resonator in reference to the copper one. A quality factor of ~6·105 was calculated for the YBCO resonator, three orders of magnitude larger than that of the copper resonator. The attenuation per unit length of the YBCO layer was smaller by more than five orders of magnitude than that of the copper.

Observations on the Growth of YBa2Cu3O7 Thin Films at Very High Laser Fluences

1995 ◽  
Vol 388 ◽  
Author(s):  
Rand R. Biggers. ◽  
M. Grant Norton ◽  
I. Maartense ◽  
T.L. Peterson ◽  
E. K. Moser ◽  
...  
Keyword(s):  
Thin Films ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Organic Chemical ◽  
High Fluences ◽  
Laser Fluences ◽  
High Laser ◽  
High Laser Fluences ◽  
Very High

AbstractThe pulsed-laser deposition (PLD) technique utilizes one of the most energetic beams available to form thin films of the superconducting oxide YBa2Cu3O7 (YBCO). IN this study we examine the growth of YBCO at very high laser fluences (25 to 40 J/cm2); a more typical fluence for PLD would be nearer to 3 J/cm2. the use of high fluences leads to unique film microstructures which, in some cases, appear to be related to the correspondingly higher moveabilities of the adatoms. Films grown on vicinal substrates, using high laser fluences, exhibited well-defined elongated granular morphologies (with excellent transition temperature, Tc, and critical current density, Jc). Films grown on vicinal substrates using off-axis magnetron sputtering, plasma-enhanced metal organic chemical vapor deposition (PE-MOCVD), or PLD at more typical laser fluences showed some similar morphologies, but less well-defined. Under certain growth conditions, using high laser fluences with (001) oriented substrates, the YBCO films can exhibit a mixture of a- and c-axis growth where both crystallographic orientations nucleate on the substrate surface at the same time, and grow in concert. the ratio of a-axis oriented to c-axis oriented grains is strongly affected by the pulse repetition rate of the laser.

Very high damage threshold Al 2 O 3 /SiO 2 dielectric coatings for excimer lasers

1994 ◽  
Author(s):  
Norbert Kaiser ◽  
Hein Uhlig ◽  
Uwe B. Schallenberg ◽  
Bernhard Anton ◽  
Ute Kaiser ◽  
...  
Keyword(s):  
Damage Threshold ◽  
Excimer Lasers ◽  
Dielectric Coatings ◽  
Very High

Deposition of Thin Films of Silicon Carbide on Fused Quartz and on Sapphire by Laser Ablation of Ceramic Silicon Carbide Targets

1992 ◽  
Vol 285 ◽  
Author(s):  
L. Rimai ◽  
R. Ager ◽  
J. Hangas ◽  
E. M. Loaothetis ◽  
Nayef Abu-ageel ◽  
...  
Keyword(s):  
Thin Films ◽  
Silicon Carbide ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Energy Gap ◽  
Fused Silica ◽  
High Resistivity ◽  
Fused Quartz ◽  
Amorphous Sic ◽  
Very High

ABSTRACTAblation of ceramic silicon carbide with 351 nm excimer radiation was used to depositSIC films on fused silica and on sapphire. For deposition temperatures above 850° C, diffraction shows the films to be crystalline with the [111] axis preferentially oriented normally to the film. Optical spectra show an indirect energy gap at 2.2 eV, near that for the cubic polytype, although the 200 diffractions are absent. Room temperature resistivities range between .02 to .1 Ωcm. Deposition below 600° C yields amorphous SiC with no diffraction bands, low and variable optical band gap and very high resistivity.

scholarly journals Very high commutation quality factor and dielectric tunability in nanocomposite SrTiO3 thin films with Tc enhanced to >300 °C

Nanoscale ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 3460-3468 ◽  
Author(s):  
Abhijeet L. Sangle ◽  
Oon Jew Lee ◽  
Ahmed Kursumovic ◽  
Wenrui Zhang ◽  
Aiping Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Quality Factor ◽  
Room Temperature ◽  
Dielectric Tunability ◽  
Nanocomposite Thin Films ◽  
Very High

We report on nanoengineered SrTiO3–Sm2O3 nanocomposite thin films with the highest reported values of commutation quality factor (CQF or K-factor) of >2800 in SrTiO3 at room temperature.

The enhanced photoelectric properties of ZnO-doped WSe2 thin film

2021 ◽  
pp. 2150082
Author(s):  
Jingyi Zhu ◽  
Xin Ding ◽  
Xiaoyu Zhang ◽  
Xiying Ma
Keyword(s):  
Thin Films ◽  
Light Absorption ◽  
High Sensitivity ◽  
Nucleation Density ◽  
Light Power ◽  
Thermal Evaporation Method ◽  
Si Substrates ◽  
Photoelectric Properties ◽  
Very High ◽  
Photoluminescence Efficiency

The photoelectric properties of ZnO-doped WSe2 thin films created on Si substrates by a thermal evaporation method were investigated. The effects of ZnO on the surface morphology, structure, photoluminescence, light absorption characteristics and electrical properties of WSe2 thin films were analyzed. It is found that the nucleation density and the crystallinity of the ZnO-doped WSe2 nanowires are higher than without doping, and the electron mobility of the doped sample is about 1.4 times that of the undoped sample. Also, doping improved the light absorption and photoluminescence efficiency. Additionally, the [Formula: see text]–[Formula: see text] curve of the ZnO-doped WSe2/Si heterojunction gradually changes from a rectification characteristic to a linear dependence, and the photocurrent increases by about four times when the light power increases from 0 to 25 mW/cm2. Moreover, the heterojunction has a very high sensitivity to operating temperature; the current significantly increases as the temperature increases to 300[Formula: see text]. With high absorptivity and photoluminescence efficiency, and sensitivity to light and temperature, ZnO-doped WSe2 film is promising for use in optoelectronic devices.

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