The Effect of Se Concentration, and Grains Size and the Energy Gap of Compacted Semiconductor (Bi2Te3)25- (Sb2Te3)75 Powders PDF

Keywords

Se, grain size, semiconductor

Abstract

This paper deals with the effect of Se impurity, grain size, and the anisotropic state on the energy gap for a pressed powder alloy of p- type semiconductor (Bi2Te3)25- (Sb2Te3)75. The D.C. four probe technique was used to measure the temperature variations of the electrical resistivity over the temperature range 120- 700K. The samples were doped with Se of concentrations 0, 0.1, 0.3, 0.5, 0.9 and 1.3 wt%, and were possessed grain sizes (L) in the range 30 > L > 20 µm, 15 > L > 10 µm, 10 > L > 5 µm and L < 5 µm. From the resistivity results the energy gaps were obtained. The results indicate the anisotropic state of the alloy, grain size, and Se concentration all affect the energy gap.