Electrical properties of n-type semiconducting chalcogenide glasses in the system Pb-Ge-Se

The electrical properties such as thermoelectric power, electrical conductivity and drift mobility have been studied on the chalcogenide glasses in the system Pb-Ge-Se. It has been found that the glasses in a certain composition range exhibit n-type conduction, as the second case in chalcogenide glasses, following the Bi-containing glasses. There were little differences in the electron and hole drift mobilities in a given glass, regardless of its conduction type. Above finding implies that the change in conduction type is not related to the relative drift mobilities of electrons and holes, but to the shift of the Fermi level toward the conduction band. The appearance of n-type conduction has been discussed in terms of chemical bonds.