Intervalley redistribution of electrons in Ge1-X SiX single crystals under hydrostatic pressure

Abstract

Ge1-xSix alloys have attractive physical properties to practical applications including direct transformation thermal energy to electric one. at high temperature range. In most cases related to investigation electrical and thermoelectrical properties of Ge1-xSix alloy single crystal have been taken into account L1-valleys of germanium and 1-valleys of silicon [1]. The influence of 1-valleys of germanium to electrical and thermoelectrical properties of n-Ge have been investigated in series of papers [2-6] and have been shown that in the straine single crystal it is remarkable especially at room and high temperatures. For this reason the follow energetic model for Ge1-xSix alloy single crystal have been considered: four L1 – and six 1-germanium valleys and six 1- silicon valleys oriented as well as the 1-germanium ones. The kinetic of all type of valleys in energetic scale have been considered and their changes in the presence of hydrostatic elastic stress. The dependences of relative numbers of electrons in L1 - , 1,Ge - and 1,Si –valleys as the function of applied hydrostatic pressure, composition and temperature have been calculated. It is shown that 1-valleys of germanium side by side with 1-valleys of silicon must be taken into consideration in a number of cases with small relative quantities of silicon in deformes single crystals.