Investigation of Thermal Properties of Thin Semiconductor Layers Deposited on a Glass Substrate by the Photothermal Deflection Technique

2010 ◽  
Vol 297-301 ◽  
pp. 537-542
Author(s):  
Imen Gaied ◽  
Mohamed Ben Rabeh ◽  
Adel Rabhi ◽  
Mounir Kanzari ◽  
Noureddine Yacoubi
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Glass Substrate ◽  
Modulation Frequency ◽  
Halogen Lamp ◽  
Square Root ◽  
Thin Semiconductor ◽  
Phase Variations ◽  
Photothermal Deflection

In this work we describe a method based on the Photothermal Deflection Technique adapted for the determination of thermal properties of thin semiconductor layers deposited on a glass substrate. The sample placed in air is heated thanks a modulated pump uniform beam coming from a halogen lamp. The thermal conductivity and the thermal diffusivity are obtained by comparing the amplitude and phase variations versus square root modulation frequency between the experimental curves and the corresponding theoretical ones. The best coincidence permits to deduce the thermal properties of the sample.

New Photothermal Deflection Method to Determine Thermal Properties of Bulk Semiconductors

2010 ◽  
Vol 297-301 ◽  
pp. 525-530
Author(s):  
Imen Gaied ◽  
Salima Lassoued ◽  
Fredéric Genty ◽  
Noureddine Yacoubi
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Modulation Frequency ◽  
Phase Variation ◽  
Sample Surface ◽  
Halogen Lamp ◽  
Bulk Semiconductors ◽  
Photothermal Deflection ◽  
Modulated Light

In this paper, we present a new Photothermal Deflection Technique (PTD) to determine thermal properties of bulk doped or undoped semiconductor such as GaAs, GaSb, InAs, etc. The method proposed here consists in covering the sample with a thin graphite layer in order to increase the photothermal signal and to ovoid any reflection on the sample surface. This method deals with the analysis of the logarithm of amplitude and phase variation of the photothermal signal versus square root modulation frequency where the sample placed in air is heated by a modulated light beam coming from a halogen lamp. So the best coincidence between experimental curves and corresponding theoretical ones gives simultaneously the best values of thermal conductivity and thermal diffusivity of the sample. These obtained values are in good agreement with those found in literature. The advantage of applying this method in this way lies in its simplicity and its sensibility to both thermal conductivity and thermal diffusivity.

Determination of the room temperature thermal conductivity of RuO2 by the photothermal deflection technique

2009 ◽  
Vol 94 (13) ◽  
pp. 131913 ◽  
Author(s):  
Dino Ferizović ◽  
Lindsay K. Hussey ◽  
Ying-Sheng Huang ◽  
Martin Muñoz
Keyword(s):  
Thermal Conductivity ◽  
Room Temperature ◽  
Photothermal Deflection

scholarly journals Determination of thermal properties of some ceiling material commonly used in Ijebu- Ode, Nigeria

2020 ◽  
Vol 9 (1) ◽  
pp. 23-27
Author(s):  
J.O. Adepitan ◽  
F.O. Ogunsanwo ◽  
J.D. Ayanda ◽  
A.A. Okusanya ◽  
A.D. Adelaja ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Tropical Rainforest ◽  
Building Construction ◽  
Thermal Resistivity ◽  
Electrical Method ◽  
Insulating Materials ◽  
Insulating Material ◽  
Range Of Values

The study investigates the thermal properties of different insulating material used in building construction in Ijebu Ode, a tropical rainforest region, south western, Nigeria. Five insulating material; asbestos, Plaster of Paris (P.O.P), PolyVinyl Chloride (PVC), hardboard and paperboard, were subjected to thermal investigation using Lee’s disc electrical method. The result obtained showed that the thermal conductivities obtained are within the range of values specified for good insulating materials. Asbestos was found to be associated with the least thermal conductivity of the value 𝟎. 𝟏𝟕𝟏𝟕 𝑾𝒎-𝟏𝑲-𝟏while PVC had the highest thermal conductivity values of 𝟏. 𝟔𝟒𝟗𝟗 𝑾𝒎-𝟏𝑲-𝟏. This may be associated with the temperature and the heat flux on the surface of the material. The results obtained for thermal conductivity, thermal resistivity and thermal diffusivity correlated favourably when compared with those of previous work from other locations. Asbestos being the material with the lowest thermal conductivity is therefore recommended for use as the suitable insulating ceiling material in the study area. Keywords: thermal conductivity, diffusivity, resistivity, Lee’s disc

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.

scholarly journals Improvement of the Thermal Properties of Sorel Cements

2020 ◽  
Author(s):  
Rim Zgueb ◽  
Amal Brichni ◽  
Noureddine Yacoubi
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Thermal Insulation ◽  
Building Material ◽  
Polyvinyl Acetate ◽  
Cement Matrix ◽  
Photothermal Deflection

Sorel cements is a promising building material for insulation applications. Indeed, the effect of polyvinyl acetate polymer on cements has been investigated. The polyvinyl acetate polymer was added to the cement matrix with a percentage of 0, 5, 10, 15 and 20% by weight of Sorel cement. The thermal properties of Sorel cement were determined by photothermal deflection technique. Thermal properties such as thermal conductivity and thermal diffusivity are measured by coincidentally the experimental curves of the photothermal signal with the best corresponding theoretical curves. The results revealed that the incorporation of polyvinyl acetate polymer enhance the thermal insulation and reduce the compressive strength of Sorel cement.

The Estimation of the Thermal Properties of Refractory Materials According to the Temperatures Acceleration Curve at the Blast Furnace Blowing-In

2015 ◽  
Vol 1095 ◽  
pp. 476-482 ◽  
Author(s):  
A.N. Dmitriev ◽  
Maxim O. Zolotykh ◽  
Yury A. Chesnokov ◽  
Oleg Yu. Ivanov ◽  
Galina Yu. Vitkina
Keyword(s):  
Thermal Conductivity ◽  
Mathematical Model ◽  
Blast Furnace ◽  
Thermal Properties ◽  
Thermal Conductivity Coefficient ◽  
Refractory Materials ◽  
Different Types ◽  
Definition Of ◽  
The Mathematical Model

In a laying of a hearth it is usually used to ten different types of the flameproof materials. The characteristics of materials declared by the manufacturer can differ from the actual. For creation of the mathematical model [1, 2] temperatures distributions in a laying of the concrete furnace it is necessary to know thermal conductivity of materials of the specific parties used at construction of the furnace. Definition of the thermal conductivity coefficient allows adapt mathematical model for specific conditions of use. The technique of determination of thermal properties of refractory materials on the temperatures acceleration curve at blowing-in of the blast furnace is described.

The Simultaneous Measurement of Thermal Conductivity, Thermal Diffusivity, and Perfusion in Small Volumes of Tissue

1984 ◽  
Vol 106 (3) ◽  
pp. 192-197 ◽  
Author(s):  
J. W. Valvano ◽  
J. T. Allen ◽  
H. F. Bowman
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Tissue Perfusion ◽  
Effective Thermal Diffusivity ◽  
Liver Preparation ◽  
Improved Technique ◽  
Power Response

An improved technique is presented for the “in-vivo” determination of thermal conductivity, thermal diffusivity, and perfusion using a self-heated spherical thermistor probe. In the presence of flow, solution of the time-dependent, probe-tissue coupled thermal model allows the measurement of “effective” thermal conductivity and “effective” thermal diffusivity, which represent the thermal properties of the perfused tissue. Perfusion can be quantified from both “effective” thermal properties. In the presence of flow, it has been shown that the transient power response does not follow t−1/2 as has been previously assumed. An isolated rat liver preparation has been developed to validate the measurement technique. Radioactive microspheres are used to determine the true perfusion from the total collected hepatic vein flow. Experimental data demonstrates the ability to quantify perfusion in small volumes of tissue.

scholarly journals Determination of thermal conductivity of rocks samples using fabricated equipment

2008 ◽  
Vol 12 (2) ◽  
pp. 119-128 ◽  
Author(s):  
Olusola Fasunwon ◽  
John Olowofela ◽  
Ojok Ocan ◽  
Olukayode Akinyemi
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Ambient Temperature ◽  
Experimental Techniques ◽  
Transient Method ◽  
Developing Nation ◽  
Rock Samples ◽  
Thermal Conductivity Of Rock

The aim of the paper is to describe how inexpensive/simple physics equipment was fabricated and used in the determination of thermal conductivity of rock samples. We used the experimental techniques known as transient method of measuring thermal properties of rock samples at ambient temperature. We investigated samples found in five locations/region (Ewekoro, Ile-Ife, Igara, Ago-Iwoye, Abeokuta) in South western Nigeria. Those samples are limestone, dolerite, marble, gneiss, and granite. Although the samples are multi-mineral as revealed by photomicrograph, the thermal conductivity results obtained 1.40, 1.50, 1.57, 1.75, and 2.94 W/m?C, respectively, are found to be consistent with the ones in literature where highly expensive and sophisticated (not easily affordable in developing nation) equipment are used. .

Investigation of Optical and Thermo-Electrical Properties of SnSb2S4 Thin Layers Using the Photothermal Deflection Technique

2010 ◽  
Vol 297-301 ◽  
pp. 531-536 ◽  
Author(s):  
Imen Gaied ◽  
Abdelaziz Gassoumi ◽  
Mounir Kanzari ◽  
Noureddine Yacoubi
Keyword(s):  
Thermal Conductivity ◽  
Optical Absorption ◽  
Energy Gap ◽  
Modulation Frequency ◽  
Thin Layers ◽  
Optical Absorption Coefficient ◽  
Glass Substrates ◽  
Type Semiconductor ◽  
Photothermal Deflection ◽  
P Type

Sulfosalt SnSb2S4 films have been deposited on glass substrates by thermal evaporation and subsequently thermally annealed in vacuum at temperatures from 100 to 250°C. Below a transition temperature of 140°C, the films are highly resistive with a dominant amorphous component, however above this temperature, the samples exhibit p+-type semiconductor behaviour with a dominant crystalline component.In this work we have studied the thermal and optical properties of these films using the photothermal deflection technique. The thermal properties are determined by comparing the experimental amplitude and phase curves variations versus square root modulation frequency of the photothermal signal to the corresponding theoretical ones. The best theoretical fitting curves are obtained for well-defined values of thermal conductivity and thermal diffusivity. The optical absorption spectrum is obtained by comparing the experimental normalized amplitude of the photothermal signal curves variations versus the wavelength to the corresponding theoretical curves variations versus the optical absorption coefficient. We have determined the energy gap by using the Tock law. From a measure of the sample’s resistance, one can deduce the electrical resistivity which may be correlated to the thermal conductivity.

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