Pressure-induced structural transformations in Bi-doped amorphous germanium sulfide

Abstract

The problem of n-type doping of amorphous germanium chalcogenides is tackled by applying a Bridgman anvil technique of high pressure. A study of Bi-doped Ge₂₀S_80-xBi_x and (Ge₄₂S₅₈)_100-xBi_x has been made up to a pressure of 100 kbar for the first time. The appearance of two pressure-induced sharp structural transitions in Ge₂₀S_80-xBi_x and one continuous transition in (Ge₄₂S₅₈)_100-xBi_x is observed. X-ray diffraction and differential thermal analysis of semiconductors (as prepared and pressure quenched) reveal the presence of two pressure-induced crystalline phases Bi₂S₃ and GeS₂. Such structural changes in the doped semiconductors may be the contributory factor in the n-type doping of the chalcogenide glass.