The Transport Properties of In2S3, Ga2Tes

Abstract

As for the . growing interest in new semiconductor materials for technology , the present work was focused on In2 S3 and Ga2Tes •crystals . This was based on the fact that when the literature was surveyed a considerable lack in the work concemmg the crystals was noticed.

The crystals were grown by two different growth techniques but both of them is a modification of the Bridgmann method . To ensure the crystallinity and avoid the possibility of presence of any other secondary phases in the grown crystals; investigations of the X -ray were done.

The structural properties were done with the aid of Computer program. The electrical conductivity was measured in two different crystallographic directions in a wide range of temperature with the help of the liquid nitrogen for the low temperature measurements. A simple pyrex cryostat and brass­ working chamber (calorimeter) were used for the electrical conductivity and •ferroelectric measurements respectively. The accuracy of the measurements was satisfactory in case of the two experiments. Physical transport properties were done bearing in mind estimation of the physical parameters which are needed for applications.

In the present work many properties were considered such as: 1-Eiectrical Conductivity The electrical conductivity was studied m nvo crystallographic directions. This was done in a wide temperature range for both crystals. The energy gap, the depth of the impurity level and anisotropic phenomena were studied. The anisotropic phenomena was discussed on the basis of Schmid's model.

2- Hall effect and Hall mobility In the same temperature range, the Hall phenomena was investigated. It was found that the Hall coefficient is a scalar quantity (direction independent). From the measurements,