Edwin, Xavier; Dr.Girijavallabhan,C P(Cochin University of Science & Technology, March , 1997)
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Abstract:
The present thesis is centered around the study of electrical and thermal
properties of certain selected photonic materials.We have studied the electrical conduction mechanism in various
phases of certain selected photonic materials and those associated with different phase
transitions occurring in them. A phase transition leaves its own impressions on the key
parameters like electrical conductivity and dielectric constant. However, the activation
energy calculation reveals the dominant factor responsible for conduction process.PA measurements of thermal diffusivity in certain other important photonic
materials are included in the remaining part of the research work presented in this
thesis. PA technique is a promising tool for studying thermal diffusivities of solid
samples in any form. Because of its crucial role and common occurrence in heat flow
problems, the thermal diffusivity determination is often necessary and knowledge of
thermal diffusivity can intum be used to calculate the thermal conductivity. Especially,knowledge of the thermal diffusivity of semiconductors is important due to its relation
to the power dissipation problem in microelectronic and optoelectronic devices which
limits their performances. More than that, the thermal properties, especially those of
thin films are of growing interest in microelectronics and microsystems because of the
heat removal problem involved in highly integrated devices. The prescribed chapter
of the present theis demonstrates how direct measurement of thermal diffusivity can be
carried out in thin films of interest in a simple and elegant manner using PA techniques.
Although results of only representative measurements viz; thermal diffusivity values in
Indium, Aluminium, Silver and CdS thin films are given here, evaluation of this
quantity for any photonic and / electronic material can be carried out using this
technique in a very simple and straight forward manner.
Description:
International School of Photonics,Cochin University of Science and Technology