INFLUENCE OF SURFACE TREATMENTS ON THE THERMOELECTRIC COEFFICENT OF GALLIUM ANTIMONIDE CRYSTALS
A. A. EBNALWALED *
Electronics and Nanodevices Lab., Physics Department, Faculty of Science, South Valley University, Qena, 83523, Egypt.
G. A. GAMAL
College of Engineering, Qassim University, KSA.
H. A. ELSHAIKH
Physics Department, Faculty of Science, Aswan University, Aswan, Egypt.
M. M. MAHASEN
Physics Department, Faculty of Science, Aswan University, Aswan, Egypt.
*Author to whom correspondence should be addressed.
Abstract
A Bridgman set-up has been modified to grow gallium antimonide crystal. the thermoelectric coefficent of the crystals was measured in a wide temperature range (240 – 460 K). The crystals were treated mechanically and chemically. The influence of polishing and etching on the thermoelectric coefficent was discussed in terms of the electrical conductivity and hence the charge carriers concentrations and their mobility. In this paper a lot of physical parameters were deduced, such as effective mass, mean free path, diffusion coefficient and diffusion length of both the majority and minority charge carriers. It was concluded in the present study that the surface treatment affected the thermoelectric coefficent and the estimated physical parameters.
Keywords: GaSb crystals, polishing, etching, surface treatments, semiconductors and thermoelectric coefficent