The Influence of Layer Structure on the Synthesis of AlSb by Laser Irradiation of Al/Sb Thin Film Couples

1983 ◽  
Vol 23 ◽  
Author(s):  
Luc Baufay ◽  
Andre Pigeolet ◽  
Rod Andrew
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Laser Irradiation ◽  
Thermal History ◽  
Laser Energy ◽  
Layer Structure ◽  
Threshold Energy ◽  
Heat Of Formation ◽  
Laser Threshold ◽  
Initial Layer

ABSTRACTWe have previously described the formation of thin AlSb films by laser irradiation of sandwich-like structures of the components, and have shown that under quasi-adiabatic conditions, the transformation can be triggered by furnishing sufficient laser energy to just melt a part of the components; subsequent progressive liberation of the heat of formation of the compound drives the reaction to completion. In this paper, we clarify some details of the reaction and we investigate the influence of initial layer structure,thermal history, and total film thickness on the required laser threshold energy.

scholarly journals Responses of Thin Film Photovoltaic Cell to Irradiation under Double Laser Beams of Different Wavelength

2013 ◽  
Vol 743-744 ◽  
pp. 937-942 ◽  
Author(s):  
Yu Chen Yuan ◽  
Chen Wu Wu ◽  
Guang Nan Chen
Keyword(s):  
Thin Film ◽  
Laser Beam ◽  
Laser Irradiation ◽  
Conversion Efficiency ◽  
Layer Structure ◽  
Cell Structure ◽  
Photovoltaic Cell ◽  
Photoelectric Conversion Efficiency ◽  
Temperature Elevation ◽  
Photoelectric Conversion

During the process of Laser beam long-range energy transmission based on the photovoltaic principle, the temperature elevation of the photovoltaic cell under Laser irradiation would greatly affect its photoelectric conversion efficiency. In this work, the heat generation mechanism of thin-film photovoltaic cell under Laser irradiation was analyzed based on the energy conversion relationship between light, electricity and heat. The output voltage characteristic of a thin film GaInP/GaAs/Ge triple-junction photovoltaic cell under irradiation of dual-wavelength Laser beam was investigated, and the results show the dependence of the conversion efficiency on the temperature and the valve effect, which was caused by the long wavelength Laser and would sharply reduce the photovoltaic conversion efficiency of short wavelength Laser. The temperature field of the multi-layer structure subjected to Laser irradiation was analyzed by finite element method, and the results indicate that the temperature elevation pattern depends on the spatial distribution of the light absorption and can be adjusted via optimizing the photovoltaic cell structure.

Waveguide refractometry as a probe of thin film optical uniformity

1997 ◽  
Vol 12 (2) ◽  
pp. 546-551 ◽  
Author(s):  
B. G. Potter ◽  
D. Dimos ◽  
M. B. Sinclair
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Layer Structure ◽  
Sol Gel ◽  
Film Surface ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Optical Characteristics ◽  
Thin Film Layer ◽  
The Impact

Optical inhomogeneities through the thickness of a sol-gel-derived, spin-coated Pb(Zr,Ti)O3 (PZT) thin film have been evaluated using prism-coupled waveguide refractometry. Unusual waveguide coupling angle behavior has been treated using a multilayer model to describe the optical characteristics of the film. Waveguide refractometry measurements, performed after incremental reductions in film thickness, were used to develop a consistent model for optical inhomogeneity through the film thickness. Specifically, a thin film layer model, consisting of alternating layers of high and low refractive index material, was found to accurately predict irregularities in transverse-electric (TE) mode coupling angles exhibited by the film. This layer structure has a spatial periodicity that is consistent with the positions of the upper film surface at intermediate firings during film synthesis. The correlation emphasizes the impact of the multistep thin-film deposition approach on the optical characteristics of the resulting thin film.

Transient Optical Transmission Measurement in Excimer-Laser Irradiation of Amorphous Silicon Films

1993 ◽  
Vol 115 (1) ◽  
pp. 178-183 ◽  
Author(s):  
H. K. Park ◽  
X. Xu ◽  
C. P. Grigoropoulos ◽  
N. Do ◽  
L. Klees ◽  
...  
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Amorphous Silicon ◽  
Laser Irradiation ◽  
Excimer Laser ◽  
Optical Transmission ◽  
Elevated Temperatures ◽  
Transient Temperature ◽  
Transmission Measurement ◽  
Excimer Laser Irradiation

The transient temperature field development during heating of an amorphous silicon (a-Si) film, deposited on a fused quartz substrate, by pulsed excimer laser irradiation is studied. Static reflectivity and transmissivity measurements are used to obtain the thin film optical properties at elevated temperatures. Experimental in-situ, transient, optical transmission data are compared with heat transfer modeling results. The variation with temperature of the material complex refractive index across the thin film thickness is taken into account. The effects of the film thickness and thermal diffusivity, as well as of the laser pulse shape, are discussed.

Excimer (XeCl) Laser Annealing of PbZr0.4Ti0.6O3 Thin Film at Low Temperature for TFT FeRAM Application

2004 ◽  
Vol 830 ◽  
Author(s):  
W. X. Xianyu ◽  
H. S. Cho ◽  
J. Y. Kwon ◽  
H.X. Yin ◽  
T. Noguchi
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Energy Density ◽  
Laser Irradiation ◽  
Excimer Laser ◽  
Laser Annealing ◽  
Laser Energy ◽  
Perovskite Phase ◽  
Hysteresis Loops ◽  
Xecl Laser

ABSTRACTIn this study, we successfully produced PbZr0.4Ti0.6O3 (PZT (40/60)) thin films with high crystallinity and high remnant polarization (Pr) at low process temperatures using pulsed excimer (XeCl) laser irradiation. In our experiments, amorphous PZT films were prepared on Pt/Ti/SiO2/Si substrates by a sol-gel method. A two-step process was used to crystallize the amorphous thin films: the films were annealed at 550°C for 10 min to initiate the nucleation of the PZT perovskite phase, and then annealed with an excimer laser heating at 400°C in a 120 Torr nitrogen gas atmosphere. Laser energy density was varied from 150 to 750 mJ/cm2 per pulse. x-ray diffraction (XRD) patterns show that 150–200 mJ/cm2 range multi-shot excimer laser irradiation drastically improved the crystallinity of the PZT perovskite phase, and FESEM photographs show that the PZT thin film has uniform-sized crystal grains. The ferroelectric properties were found to depend on the laser energy density and shot number. Before the laser annealing, the films show hysteresis loops with low Pr and the loops do not saturate. After laser annealing, the films show highly saturated hysteresis loops, with the Pr increasing from 2.2 μC/cm2 to 23.0 μC/cm2. We also propose a new technology for fabrication of thin film transistor (TFT)-driven FeRAM devices on arbitrary insulator substrate such as on glass.

Pulsed Laser Deposition Parameter Optimization for Growth of Alumina (Al2O3) Thin Film on Silicon (100)

2003 ◽  
Vol 788 ◽  
Author(s):  
Xinyu Wang ◽  
Sergey Yarmolenko ◽  
Dhananjay Kumar ◽  
Zhigang Xu ◽  
Jagannathan Sankar
Keyword(s):  
Thin Film ◽  
Elastic Modulus ◽  
Film Thickness ◽  
Substrate Temperature ◽  
Pulsed Laser Deposition ◽  
Laser Energy ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Crystalline Phases ◽  
Deposition Parameter

ABSTRACTPulsed laser deposition (PLD) technique was used to grow alumina (Al2O3) thin films on (100) silicon substrate under different deposition conditions. The relationship between Al2O3thin film thickness, hardness, elastic modulus, surface morphology and PLD parameters such as laser energy and substrate temperature was investigated. The Film thickness was found to increase with an increase in laser energy and to decrease with an increase in substrate temperature. The film hardness and elastic modulus increases as substrate temperature increases. We have also shown that films are amorphous at lower substrate temperatures and transform to mixture of amorphous and crystalline phases. The ratio of amorphous to crystalline phases decreases with increase in temperature. The surfaces of Al2O3film grown using PLD was found very smooth with least root square roughness less than 2 nm.

Optical Birefringence to Determine Morphological Changes in Low-K Thin Film CVD Polymers

1998 ◽  
Vol 511 ◽  
Author(s):  
Jay J. Senkevich ◽  
Viktor Simkovic ◽  
Seshu B. Desu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Stability ◽  
Dielectric Constant ◽  
Film Thickness ◽  
Thermal History ◽  
Deposition Temperature ◽  
Morphological Changes ◽  
High Thermal Stability ◽  
Optical Birefringence

ABSTRACTA great interest exists to reduce power consumption, cross-talk, and RC-delay in ULSI devices by replacing SiO2(k=3.9−4.3) with a polymeric material (k<3.0). Unlike SiO2, polymeric thin films exhibit a complex morphology which varies with the polymer's thermal history, deposition temperature, and film thickness. Since the morphology of the polymer thin film ultimately affects its properties such as its dielectric constant, methods need to be developed to understand the morphological changes in polymer thin films. Further, the polymer thin films must exhibit a high thermal stability due to the relatively high back-end-of-line (BEOL) processing temperature. The polymers which exhibit high thermal stability often contain a mainchain benzene ring. Since benzene has a high anisotropic molecular polarizability, optical birefringence can be used to monitor the polymer chain conformation as a function of the polymer's thermal history, thickness or deposition conditions. Poly(p-xylylene) and poly(tetraflouro-p-xylylene) are shown to have a large negative birefringence, increasing until polymer decomposition. Poly(p-xylylene) becomes increasingly more negatively birefringent after a crystallographic phase change at 220°C. A high negative birefringence results in a large in-plane capacitance, negatively impacting the polymers potential benefit. owever, poly(chlorop-xylylene) and poly(dichloro-p-xylylene) exhibit positive birefringence, which increases until their crystalline melting points at ∼290°C and ∼380°C and thereafter decreases due to film disruption. Conclusions will be drawn based on this positive birefringence for the future molecular design of CVD polymers to decrease their in-plane dielectric constant. Urther poly(chloro-p-xylylene) and poly(p-xylylene) are investigated as a function of deposition temperature and film thickness.

scholarly journals Carbon-coated magnetic particles increase tissue temperatures after laser irradiation

2015 ◽  
Vol 08 (05) ◽  
pp. 1550018 ◽  
Author(s):  
Shupeng Liu ◽  
Na Chen ◽  
Fufei Pang ◽  
Zhengyi Chen ◽  
Tingyun Wang
Keyword(s):  
Laser Irradiation ◽  
Magnetic Particles ◽  
Laser Energy ◽  
Thermal Therapy ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fbg Sensor ◽  
Transmission Electron ◽  
Carbon Coated

Purpose: This work focused on the investigation the hyperthermia performance of the carbon-coated magnetic particles (CCMPs) in laser-induced hyperthermia. Materials and methods: We prepared CCMPs using the organic carbonization method, and then characterized them with transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis) spectrophotometry, vibrating sample magnetometer (VSM) and X-ray diffraction (XRD). In order to evaluate their performance in hyperthermia, the CCMPs were tested in laser-induced thermal therapy (LITT) experiments, in which we employed a fully distributed fiber Bragg grating (FBG) sensor to profile the tissue's dynamic temperature change under laser irradiation in real time. Results: The sizes of prepared CCMPs were about several micrometers, and the LITT results show that the tissue injected with the CCMPs absorbed more laser energy, and its temperature increased faster than the contrast tissue without CCMPs. Conclusions: The CCMPs may be of great help in hyperthermia applications.

Organic thin film thickness-dependent photocurrents polarity in graphene heterojunction phototransistor

Carbon ◽  
2021 ◽  
Vol 178 ◽  
pp. 506-514
Author(s):  
Meiyu He ◽  
Jiayue Han ◽  
Xingwei Han ◽  
Jun Gou ◽  
Ming Yang ◽  
...  
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Organic Thin Film ◽  
Thin Film Thickness
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