Title:
|
Photothermal deflection measurement on heat transport in GaAs epitaxial layers |
Author:
|
Girijavallabhan, C P; Radhakrishnan, P; Nampoori, V P N; Sajan, D George
|
Abstract:
|
In this paper, we report the in-plane and cross-plane measurements of the thermal diffusivity of double
epitaxial layers of n-type GaAs doped with various concentrations of Si and a p-type Be-doped GaAs layer
grown on a GaAs substrate by the molecular beam epitaxial method, using the laser-induced nondestructive
photothermal deflection technique. The thermal diffusivity value is evaluated from the slope of the graph of the
phase of the photothermal deflection signal as a function of pump-probe offset. Analysis of the data shows that
the cross-plane thermal diffusivity is less than that of the in-plane thermal diffusivity. It is also seen that the
doping concentration has a great influence on the thermal diffusivity value. Measurement of p-type Be-doped
samples shows that the nature of the dopant also influences the effective thermal diffusivity value. The results
are interpreted in terms of a phonon-assisted heat transfer mechanism and the various scattering process
involved in the propagation of phonons. |
URI:
|
http://dyuthi.cusat.ac.in/purl/1808
|
Date:
|
2003-10-16 |