scholarly journals Influence of lateral heat diffusion on the thermal impedance measurement of photovoltaic panels

2013 ◽  
Vol 112 ◽  
pp. 1-5 ◽  
Author(s):  
G. De Mey ◽  
J. Wyrzutowicz ◽  
A. De Vos ◽  
W. Marańda ◽  
A. Napieralski
Keyword(s):  
Impedance Measurement ◽  
Heat Diffusion ◽  
Thermal Impedance ◽  
Photovoltaic Panels ◽  
Lateral Heat

Thermal Properties of Thin Metallic Layer Deposited on Insulators: Effect of the Interface on the Independent Determination of the Thermal Diffusivity and Conductivity of the Layer

2008 ◽  
Author(s):  
Danie`le Fournier ◽  
Jean Paul Roger ◽  
Christian Fretigny
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Thermal Resistance ◽  
Thermal Contact ◽  
Heat Diffusion ◽  
Metallic Layer ◽  
Good Thermal Contact ◽  
Lateral Heat

Lateral heat diffusion thermoreflectance is a very powerful tool for determining directly the thermal diffusivity of layered structures. To do that, experimental data are fitted with the help of a heat diffusion model in which the ratio between the thermal conductivity k and the thermal diffusivity D of each layer is fixed, and the thermal properties of the substrate are known. We have shown in a previous work that it is possible to determine independently the thermal diffusivity and the thermal conductivity of a metallic layer deposited on an insulator, by taking into consideration all the data obtained at different modulation frequencies. Moreover, it is well known that to prevent a lack of adhesion of a gold film deposited on substrates like silica, an intermediate very thin (Cr or Ti) layer is deposited to assure a good thermal contact. We extend our previous work: the asymptotic behaviour determination of the surface temperature wave at large distances from the modulated point heat source for one layer deposited on the substrate to the two layers model. In this case (very thin adhesion coating whose thermal properties and thickness are known), it can be establish that the thermal diffusivity and the thermal conductivity of the top layer can still be determined independently. It is interesting to underline that the calculus can also be extended to the case of a thermal contact resistance which has often to be taken into account between two solids. We call thermal resistance a very thin layer exhibiting a very low thermal conductivity. In this case, the three parameters we have to determine are the thermal conductivity and the thermal diffusivity of the layer and the thermal resistance. We will show that, in this case, the thermal conductivity of the layer is always obtained independently of a bound of the couple thermal resistance – thermal diffusivity, the thermal diffusivity being under bounded and the thermal resistance lower bounded. Experimental results on thin gold layers deposited on silica with and without adhesion layers are presented to illustrate the method. Discussions on the accuracy will also be presented.

Independent Determination of the Thermal Diffusivity and Conductivity of a Thin Metallic Layer Deposited on Silica

2008 ◽  
Author(s):  
Christian Fretigny ◽  
Jean Paul Roger ◽  
Li Liu ◽  
Danie`le Fournier
Keyword(s):  
Thermal Diffusivity ◽  
Careful Analysis ◽  
Thin Layers ◽  
Heat Diffusion ◽  
Bulk Materials ◽  
Thermal Insulator ◽  
Independent Determination ◽  
Lateral Temperature ◽  
Lateral Heat

It is well known that the thermal parameters of materials confined in thin layers may significantly differ from their bulk value. Lateral heat diffusion thermoreflectance experiment is a very powerful tool for determining directly the thermal diffusivity of bulk materials and of layered structure. Nevertheless, in the latter case, experimental data are fitted with the help of a heat diffusion model in which the layer thermal conductivity and thermal diffusivity are taken together into consideration. In this paper, we show that both parameters can be determined independently, in the case of a thermal conductive layer deposited on a thermal insulator, with a careful analysis of the amplitude and the phase of the lateral temperature field associated to a point source.

Non-Destructive Measurement of Deep Embedded Defects in Silicon using Photoacoustic Microscope (PAM)

2006 ◽  
Vol 914 ◽  
Author(s):  
Lu Xu ◽  
Donnacha Lowney ◽  
Patrick J McNally ◽  
Eva Gomez Fernandez ◽  
Jennifer Stopford
Keyword(s):  
Heat Diffusion ◽  
Defect Characterization ◽  
Back Side ◽  
Gas Cell ◽  
Subsurface Defect ◽  
Phase Images ◽  
Destructive Measurement ◽  
D Model ◽  
Non Destructive ◽  
Lateral Heat

AbstractAn automatic gas cell photoacoustic microscope has been used to characterize two laser machined air trenches in a silicon substrate from the back side. Both amplitude and phase images reveal the subsurface features. The frequency dependence of the photoacoustic signals with different laser spot sizes was compared with a 1-D model. The effect of lateral heat diffusion on subsurface defect characterization was investigated and the results can be applied to other photothermal techniques.

Thermal impedance measurement of integrated inductors on bulk silicon substrate

2017 ◽  
Vol 73 ◽  
pp. 54-59 ◽  
Author(s):  
M. Kałuża ◽  
B. Więcek ◽  
G. De Mey ◽  
A. Hatzopoulos ◽  
V. Chatziathanasiou
Keyword(s):  
Silicon Substrate ◽  
Impedance Measurement ◽  
Thermal Impedance ◽  
Bulk Silicon ◽  
Integrated Inductors

scholarly journals Silica-waveguide thermooptic phase shifter with low power consumption and low lateral heat diffusion

1993 ◽  
Vol 5 (12) ◽  
pp. 1415-1418 ◽  
Author(s):  
B.A. Moller ◽  
L. Jensen ◽  
C. Laurent-Lund ◽  
C. Thirstrup
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
Phase Shifter ◽  
Heat Diffusion ◽  
Low Power Consumption ◽  
Lateral Heat
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