Transient Thermal Characterization of ErAs/In0.53Ga0.47As Thermoelectric Module

2007 ◽  
Author(s):  
Y. Ezzahri ◽  
R. Singh ◽  
K. Fukutani ◽  
Z. Bian ◽  
A. Shakouri ◽  
...  
Keyword(s):  
Metallic Nanoparticles ◽  
Thermoelectric Module ◽  
Thermal Characterization ◽  
Hot Electrons ◽  
Thermoelectric Power Factor ◽  
Scattering Centers ◽  
Network Identification ◽  
Transient Thermal

Embedded metallic nanoparticles in semiconductors have recently been proven to be of great interest for thermoelectric applications. These metallic nanoparticles play the role of scattering centers for phonons and a source of doping for electrons; they reduce simultaneously the thermal conductivity and increase the thermoelectric power factor of the semiconductor. It has also shown that metal/semiconductor heterostructures can be used to break the crystal momentum symmetry for hot electrons in thermionic devices, then increasing the number of electrons participating in transport. A thermoelectric module of 200 N-P pairs of InGaAlAs with embedded ErAs metallic nanoparticles has been fabricated. Network Identification by Deconvolution (NID) technique is then applied for transient thermal characterization of this thermoelectric module. The combination of this new representation of the dynamic behavior of the packaged device with high resolution thin film temperature measurement allows us to obtain information about heat transfer within the thermoelectric module. This is used to extract the thermal resistances and heat capacitances of the module.

scholarly journals Optical and Thermal Analysis of Secondary Optics in Light Emitting Diodes’ Packaging: Analysis of MR16 Lamp

2021 ◽  
Vol 2116 (1) ◽  
pp. 012121
Author(s):  
Mohammad Azarifar ◽  
Ceren Cengiz ◽  
Mehmet Arik
Keyword(s):  
Heat Dissipation ◽  
Light Emitting Diodes ◽  
Thermal Characterization ◽  
Thermal Control ◽  
Light Extraction Efficiency ◽  
Thickness Effect ◽  
Package Design ◽  
Light Emitting

Abstract Optical and thermal control are two main factors in package design process of lighting products, specifically light emitting diodes (LEDs). This research is aimed to study the role of secondary optics in opto-thermal characterization of LED packages. Novel thin total internal reflection (TIR) multifaceted reflector (MR) lens is modelled and optimized in Monte-Carlo ray-tracing simulations for MR16 package, regarded as one of the widely used LED lighting products. With criteria of designing an optical lens with 50% reduced thickness in comparison to commercially available lenses utilized in MR16 packages, nearly same light extraction efficiency and more uniform beam angles are achieved. Optical performance of the new lens is compared with the experimental results of the MR16 lamp with conventional lens. Only 2.3% reduction in maximum light intensity is obtained while lens size reduction was more than 25%. Based on the detailed CAD design, heat transfer simulations are performed comparing the lens thickness effect on heat dissipation of MR16 lamp. It was observed that using thinner lenses can reduce the lens and chip temperature, which can result in improved light quality and lifetime of both lens and light source.

scholarly journals Thermal characterization of the active layer at the Limnopolar Lake CALM-S site on Byers Peninsula (Livingston Island), Antarctica

Solid Earth ◽  
2014 ◽  
Vol 5 (2) ◽  
pp. 721-739 ◽  
Author(s):  
M. A. de Pablo ◽  
M. Ramos ◽  
A. Molina
Keyword(s):  
Thermal Behavior ◽  
Active Layer ◽  
Thermal Characterization ◽  
Active Layer Thickness ◽  
Freezing And Thawing ◽  
Thermal Amplitude ◽  
Permafrost Table ◽  
Different Depths

Abstract. The Limnopolar Lake site (A25), of the Circumpolar Active Layer Monitoring-South network (CALM-S), is located on Byers Peninsula, where the active layer thickness is monitored systematically (by mechanical probing during the thawing season and by temperature devices continuously since 2009). Air, surface, snow and ground temperature devices have been installed to monitor ground thermal behavior, which is presented and characterized here. We use the air and ground mean daily temperature values to define the following parameters: maximum, minimum and mean temperatures, the zero annual thermal amplitude, and the depth and position of the top of the permafrost table. The freezing and thawing seasons (defining their starting dates as well as their length) and the existence of zero curtain periods have also been established. We also derive apparent thermal diffusivity and plot thermograms to study the thermal behavior of the ground at different depths and seasons. After this complete thermal characterization of the active layer, we propose the potential existence of a permafrost table at approximately 130 cm in depth as well as a former transitional layer above it, and discuss the role of water in connection with the thermal behavior of the ground during the study period.

Transient Thermal Characterization of a Stacked Multichip Package

2007 ◽  
Vol 4 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Kimmo Kaija ◽  
Pekka Heino
Keyword(s):  
Steady State ◽  
Flip Chip ◽  
Thermal Characterization ◽  
Transient Behavior ◽  
Fe Model ◽  
Thermal Test ◽  
Transient Thermal ◽  
Temperature Responses

This paper is a case study of the thermal behavior of a stacked multichip package (SMCP). The aim is to measure temperature responses when heat is dissipated on different dice and to characterize the behavior with a compact thermal model (CTM) that accurately models steady-state and transient responses with a simple thermal RC -network. The measured package consists of three stacked layers, where each layer has one thinned flip chip attached die on an aramid interposer. The package's thermal responses were measured with thermal test dice that contain heaters and temperature sensors. The package was modeled with a finite element method (FEM) and the simulated temperature responses showed reasonable agreement with measured data. The FE model was further used to provide reference thermal data under different boundary conditions for CTM synthesis. The obtained CTM models accurately the steady-state and transient behavior and can be used as simplified model of the measured SMCP for further thermal analysis.

The Protective Role of Poly(Borosiloxanes)-Derived Ceramics in Carbon Fiber Composites

2008 ◽  
Vol 587-588 ◽  
pp. 182-186 ◽  
Author(s):  
Renato Luiz Siqueira ◽  
Luiz Claudio Pardini ◽  
Inez Valéria Pagotto Yoshida ◽  
Marco Antônio Schiavon
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Thermal Protection ◽  
Ceramic Matrix Composites ◽  
Thermal Characterization ◽  
Protective Role ◽  
Carbon Fiber Composites ◽  
Matrix Composites

This work reports the synthesis and thermal characterization of poly(borosiloxanes) (PBS) derived from methyltrietoxysilane (MTES) and vinyltriethoxysilane (VTES), aiming to use these polymers as precursors of ceramic matrices for the protection of carbon fibers in ceramic matrix composites (CMCs). The resulting materials exhibited better thermal stability than the carbon fiber, especially the Cfiber/SiBCO composite derived of the methyltriethoxysilane (MTES) system prepared with a B/Si ratio of 0.5. This study showed that poly(borosiloxanes) are promising materials for the oxidation protection of carbon fibers, and consequently for thermal protection systems.

Transient thermal gratings at surfaces for thermal characterization of bulk materials and thin films

1995 ◽  
Vol 61 (3) ◽  
pp. 253-261 ◽  
Author(s):  
O.W. K�ding ◽  
H. Skurk ◽  
A.A. Maznev ◽  
E. Matthias
Keyword(s):  
Thin Films ◽  
Thermal Characterization ◽  
Bulk Materials ◽  
Transient Thermal

6 Watt Segmented Power Generator Modules using Bi2Te3 and (InGaAs)1-x(InAlAs)x Elements Embedded with ErAs Nanoparticles

2008 ◽  
Vol 1129 ◽  
Author(s):  
Gehong Zeng ◽  
Je-Hyeong Bahk ◽  
Ashok T Ramu ◽  
John E Bowers ◽  
Hong Lu ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Metallic Nanoparticles ◽  
Thermoelectric Generator ◽  
Power Generator ◽  
Erbium Arsenide ◽  
Long Wavelength ◽  
Potential Barriers ◽  
Scattering Centers ◽  
Fabrication And Characterization

AbstractWe report the fabrication and characterization of segmented element power generator modules of 16 x 16 thermoelectric elements consisting of 0.8 mm thick Bi2Te3 and 50 μm thick ErAs:(InGaAs)1-x(InAlAs)x with 0.6% ErAs by volume. Erbium Arsenide metallic nanoparticles are incorporated to create scattering centers for middle and long wavelength phonons, and to form local potential barriers for electron filtering. The thermoelectric properties of ErAs:(InGaAs)1-x(InAlAs)x were characterized in terms of electrical conductivity and Seebeck coefficient from 300 K up to 830 K. Generator modules of Bi2Te3 and ErAs:(InGaAs)1-x(InAlAs)x segmented elements were fabricated and an output power of 6.3 W was measured. 3D finite modeling shows that the performance of thermoelectric generator modules can further be enhanced by the improvement of the thermoelectric properties of the element materials, and reducing the electrical and thermal parasitic losses.

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