Pressure induced effects in bulk amorphous n-type semiconductors (GeSe_3.5)_100-xBi_x

Abstract

The effect of pressure on the electrical resistivity of amorphous n-type (GeSe_3.5)_100-xBi_x been studied in a Bridgeman anvil system up to a pressure of 90 kbar down to liquid nitrogen temperature. A continuous amorphous semiconductor to metal-like solid transition in the undoped GeSe_3.5 is observed at room temperature. Incorporation of Bi in the GeSe_3.5 network is found to significantly disturb the behaviour of the resistivity with pressure. With increasing Bi concentration a much broader variation in resistivity with pressure is observed. The temperature dependence of the resistivity and activation energy at different pressures is also measured and they are found to be composition dependent. Results are discussed in the light of the Phillips Model of ordered clusters in chalcogenide semiconductors.