Electrical properties of GeSbSe glasses

The dc and ac conductivities of glasses of the system GeSbSe (with the general formula Ge_xSb₁₀Se_90?x have been studied. The dc conductivity results indicate a maximum in the glass transition temperature and activation energy and a minimum in conductivity for the composition Ge₂₅Sb₁₀Se₆₅. These results have been explained on the basis of the prevalent structural arrangement wherein structural units of GeSe₂ and Sb₂Se₃ are dispersed among excess Se or Ge. Based on this picture, a model has been developed which accounts for the observed dependence of conductivity on composition at any temperature. The ac results have been utilized to find the hopping conductivity as a function of composition; the characteristics of lone pair amorphous semiconductors seem to account for the observed features.