Doping in Chalcogendie Semiconductors : Impedance Spectroscopic Study

Chalcogenide semiconductors, counterpart of their crystalline form are widely known for their industrial applications. Different approaches are applied to study the conduction mechanism to explore these materials. The measurements on electrical and photoelectrical properties of a-Sb2Se3, Ag-Sb2Se3 and Se25Ge20Te55 over a wide range of frequency (5 Hz-100 kHz), and temperature (230-340 K) under dark and illuminated conditions indicate that Ag-doped chalcogenide is sensitive to thermal and electrical stresses and hence could be used in various device applications. It is clear that pure and doped chalcogenides behave very differently on the grounds of electrical and photo-electrical properties. The available theoretical models for amorphous semiconductors are used to explain the observed behaviour of the chalcogenides and modifications are suggested. Further, a possible applications of Ag-Sb2Se3 as thermal/voltage sensor and Se25Ge20Te55 as optoelectronic switch has also been studied.