THERMAL CHARACTERIZATION OF GaAsN THIN FILMS BY PULSED PHOTOTHERMAL REFLECTANCE TECHNIQUE

2004 ◽  
Vol 03 (06) ◽  
pp. 781-787 ◽  
Author(s):  
YIMIN ZHAO ◽  
GEORGE CHEN ◽  
SHANZHONG WANG ◽  
SOON FATT YOON
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Gaas Substrate ◽  
Room Temperature ◽  
Molecular Beam ◽  
Thermal Characterization ◽  
Gallium Arsenic Nitride ◽  
Dependent Relationship ◽  
20 Nm

Thermal conductivity of Gallium Arsenic Nitride ( GaAsN ) epilayer on Gallium Arsenide ( GaAs ) substrate prepared by Molecular Beam Epitaxy technique was measured using pulsed photothermal reflectance technique. Within the thickness ranging from 20 nm to 80 nm, no thickness dependent relationship with thermal conductivity of GaAsN epilayer was found, and the average thermal conductivity is about 28 W/mK at room temperature.

Evaluation of Thermal Characterization Techniques and Tools for Thermal Conductivity Measurement of Sub 100 Angstrom Thick Silicon Layers

2007 ◽  
Author(s):  
Keivan Etessam-Yazdani ◽  
Mehdi Asheghi
Keyword(s):  
Thermal Conductivity ◽  
Conductivity Measurement ◽  
Thermal Characterization ◽  
Phonon Transport ◽  
Thermal Conductivity Measurement ◽  
Great Success ◽  
Silicon Structures ◽  
Thin Silicon ◽  
20 Nm

Experimental measurement of thermal conductivity is considered the most reliable tool for the study of phonon transport in ultra-thin silicon structures. While there has been a great success in thermal conductivity measurement of ultra-thin silicon layers down to 20 nm over the past decade, it is not clear if the existing techniques and tools can be extended to the measurements of sun 100 Angstrom layers. In this paper, an analytical study of the feasibility of electrical Joule heating and thermometry in patterned metal bridges is presented. It is concluded that thermal conductivity of silicon layers as thin as 5 nm can be obtained (uncertainty 20%) by performing steady-state measurements using an on-substrate nanoheater structure. The thermal characterization of silicon layers as thin as 1 nm may be possible using frequency domain measurements.

scholarly journals Synthesis and Characterization of Al- and SnO2-Doped ZnO Thermoelectric Thin Films

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6929
Author(s):  
Giovanna Latronico ◽  
Saurabh Singh ◽  
Paolo Mele ◽  
Abdalla Darwish ◽  
Sergey Sarkisov ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Room Temperature ◽  
Bulk Material ◽  
Laser Deposition ◽  
Sno2 Thin Film ◽  
Order Of Magnitude ◽  
Doped Zno ◽  
Thermoelectric Thin Films

The effect of SnO2 addition (0, 1, 2, 4 wt.%) on thermoelectric properties of c-axis oriented Al-doped ZnO thin films (AZO) fabricated by pulsed laser deposition on silica and Al2O3 substrates was investigated. The best thermoelectric performance was obtained on the AZO + 2% SnO2 thin film grown on silica, with a power factor (PF) of 211.8 μW/m·K2 at 573 K and a room-temperature (300 K) thermal conductivity of 8.56 W/m·K. PF was of the same order of magnitude as the value reported for typical AZO bulk material at the same measurement conditions (340 μW/m·K2) while thermal conductivity κ was reduced about four times.

scholarly journals Особенности теплопереноса в гетероструктурах Al-=SUB=-x-=/SUB=-Ga-=SUB=-1-x-=/SUB=-N/GaN на сапфире

2020 ◽  
Vol 62 (4) ◽  
pp. 635
Author(s):  
Д.А. Чернодубов ◽  
И.О. Майборода ◽  
М.Л. Занавескин ◽  
А.В. Инюшкин
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Molecular Beam Epitaxy ◽  
Concentration Dependence ◽  
Room Temperature ◽  
Molecular Beam ◽  
Local Heating ◽  
Thin Layers ◽  
Thermal Conductivity Model ◽  
Measured Thermal Conductivity

Thermal conductivity of thin layers of AlxGa1-xN/GaN (0.05≤ x≤1) heterostructures on sapphire grown with molecular beam epitaxy has been measured. Thermal conductivity values of AlxGa1-xN и GaN thin films at room temperature have been obtained. Concentration dependence of thermal conductivity has been analyzed with the virtual crystal thermal conductivity model. Thermal transport in the structure considering local heating has been simulated numerically in order to find optimal structure layers` thicknesses allowing high thermal conductivity value.

Photothermal Techniques for Materials Characterization and Live Cells Monitoring

2009 ◽  
Vol 74 ◽  
pp. 101-104
Author(s):  
George C.K. Chen ◽  
Srivathsan Vasudevan ◽  
Teu Choon Kiat
Keyword(s):  
Thin Films ◽  
Phase Contrast ◽  
High Spatial Resolution ◽  
Mdck Cells ◽  
Thermal Characterization ◽  
Live Cells ◽  
Photothermal Techniques ◽  
20 Nm ◽  
Conductivity Of Thin Films

Photothermal technology can be applied for thermal characterization of thin films and studying biological live cells. Using pulsed photothermal reflectance technique, thermal conductivity of thin films ranging from 20 nm to a few microns can be determined. Photothermal imaging (PTI) technique can provide ultra high spatial resolution and no fluorescence molecules are required. Comparison with normal phase contrast images, PT images reveal temperature distribution and more information on the intracellular components. Photothermal response (PTR) technique can provide high temporal resolutions. In monitoring the dying process of MDCK cells, significant changes in the PTR signals can be observed whereas unnoticeable changes are found in the images.

Processing by Pulsed Laser Deposition and Structural, Morphological and Chemical Characterization of Bi-Pb-Sr-Ca-Cu-O and Bi-Pb-Sb-Sr-Ca-Cu-O Thin Films

2010 ◽  
Vol 75 ◽  
pp. 202-207
Author(s):  
Victor Ríos ◽  
Elvia Díaz-Valdés ◽  
Jorge Ricardo Aguilar ◽  
T.G. Kryshtab ◽  
Ciro Falcony
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Chemical Characterization ◽  
Laser Deposition ◽  
Nominal Composition ◽  
Deposition Parameters ◽  
The Relationship

Bi-Pb-Sr-Ca-Cu-O (BPSCCO) and Bi-Pb-Sb-Sr-Ca-Cu-O (BPSSCCO) thin films were grown on MgO single crystal substrates by pulsed laser deposition. The deposition was carried out at room temperature during 90 minutes. A Nd:YAG excimer laser ( = 355 nm) with a 2 J/pulse energy density operated at 30 Hz was used. The distance between the target and substrate was kept constant at 4,5 cm. Nominal composition of the targets was Bi1,6Pb0,4Sr2Ca2Cu3O and Bi1,6Pb0,4Sb0,1Sr2Ca2Cu3OSuperconducting targets were prepared following a state solid reaction. As-grown films were annealed at different conditions. As-grown and annealed films were characterized by XRD, FTIR, and SEM. The films were prepared applying an experimental design. The relationship among deposition parameters and their effect on the formation of superconducting Bi-system crystalline phases was studied.

Room‐temperature excitonic optical nonlinearities of molecular beam epitaxially grown ZnSe thin films

1988 ◽  
Vol 52 (3) ◽  
pp. 182-184 ◽  
Author(s):  
N. Peyghambarian ◽  
S. H. Park ◽  
S. W. Koch ◽  
A. Jeffery ◽  
J. E. Potts ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Molecular Beam ◽  
Optical Nonlinearities ◽  
Znse Thin Films

Characterization of the order-annealing response of nanostructured iron-palladium based ferromagnetic thin-films

2001 ◽  
Vol 703 ◽  
Author(s):  
Huiping Xu ◽  
Adam T. Wise ◽  
Timothy J. Klemmer ◽  
Jörg M. K. Wiezorek
Keyword(s):  
Thin Films ◽  
Grain Growth ◽  
Room Temperature ◽  
Si Substrate ◽  
Ferromagnetic Thin Films ◽  
Precipitation Reactions ◽  
Post Deposition ◽  
Xrd And Tem ◽  
Iron Palladium

ABSTRACTA combination of XRD and TEM techniques have been used to characterize the response of room temperature magnetron sputtered Fe-Pd thin films on Si-susbtrates to post-deposition order-annealing at temperatures between 400-500°C. Deposition produced the disordered Fe-Pd phase with (111)-twinned grains approximately 18nm in size. Ordering occurred for annealing at 450°C and 500°C after 1.8ks, accompanied by grain growth (40-70nm). The ordered FePd grains contained (111)-twins rather than {101}-twins typical of bulk ordered FePd. The metallic overlayers and underlayers selected here produced detrimental dissolution (Pt into Fe-Pd phases) and precipitation reactions between Pd and the Si substrate.

Anisotropic Thermal Conductivity of a Si/Ge Quantum Dot Superlattice

2000 ◽  
Author(s):  
Theodorian Borca-Tasciuc ◽  
Weili Liu ◽  
Jianlin Liu ◽  
Kang L. Wang ◽  
Gang Chen
Keyword(s):  
Thermal Conductivity ◽  
Quantum Dots ◽  
Molecular Beam ◽  
Conductivity Measurements ◽  
Transport Models ◽  
3Ω Method ◽  
Superlattice Structure ◽  
Anisotropic Thermal Conductivity ◽  
Ge Quantum Dot

Abstract In this work, we present experimental results on the in-plane and cross-plane thermal conductivity characterization of a Si/Ge quantum-dots superlattice structure. The quantum-dots superlattice was grown by molecular-beam-epitaxy and self-organization. The anisotropic thermal conductivity measurements are performed by a differential two-wire 3ω method. The measured in-plane and cross-plane thermal conductivity values show a different temperature behavior. The results are compared and explained with heat transport models in superlattices.

Structural Evolution Upon Annealing of Multi-Layer Si/Fe Thin Films Prepared by Magnetron Sputtering

2007 ◽  
Vol 561-565 ◽  
pp. 1161-1164
Author(s):  
Xiao Na Li ◽  
Bing Hu ◽  
Chuang Dong ◽  
Xin Jiang
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Room Temperature ◽  
Structural Evolution ◽  
Radio Frequency Magnetron Sputtering ◽  
Transmission Electron ◽  
Direct Band ◽  
The Stability ◽  
Sputtering System

Fe/Si multi-layer films were fabricated on Si (100) substrates utilizing radio frequency magnetron sputtering system. Si/β-FeSi2 structure was found in the films after the deposition. Structural characterization of Fe-silicide sample was performed by transmission electron microscopy, to explore the dependence of the microstructure of β-FeSi2 film on the preparation parameters. It was found that β-FeSi2 particles were formed after the deposition without annealing, whose size is less than 20nm ,with a direct band-gap of 0.94eV in room temperature. After annealing at 850°C, particles grow lager, however the stability of thin films was still good.

Long-term Room Temperature Instability in Thermal Conductivity of InGaZnO Thin Films

MRS Advances ◽  
2016 ◽  
Vol 1 (22) ◽  
pp. 1631-1636 ◽  
Author(s):  
Boya Cui ◽  
D. Bruce Buchholz ◽  
Li Zeng ◽  
Michael Bedzyk ◽  
Robert P. H. Chang ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Conductivity ◽  
Room Temperature ◽  
Storage Time ◽  
Laser Deposition ◽  
Low Oxygen ◽  
X Ray Diffraction ◽  
3Ω Method ◽  
X Ray

ABSTRACTThe cross-plane thermal conductivities of InGaZnO (IGZO) thin films in different morphologies were measured on three occasions within 19 months, using the 3ω method at room temperature 300 K. Amorphous (a-), semi-crystalline (semi-c-) and crystalline (c-) IGZO films were grown by pulsed laser deposition (PLD), followed by X-ray diffraction (XRD) for evaluation of film quality and crystallinity. Semi-c-IGZO shows the highest thermal conductivity, even higher than the most ordered crystal-like phase. After being stored in dry low-oxygen environment for months, a drastic decrease of semi-c-IGZO thermal conductivity was observed, while the thermal conductivity slightly reduced in c-IGZO and remained unchanged in a-IGZO. This change in thermal conductivity with storage time can be attributed to film structural relaxation and vacancy diffusion to grain boundaries.

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