HIGH FIELD CONDUCTION IN a- Se70Te30-XCdX THIN FILMS:

In general, in case of semiconductors, conductivity (σ) varies exponentially with temperature (T), i.e., σ = σ0 exp (- ∆E / k T) where ∆E is the activation energy and σ0 is called the pre-exponential factor. In most of the semiconducting materials, σ0 does not depend on ∆E. However, in many organic and amorphous semiconductors, σ0 is found to increase exponentially with ∆E. This is called Meyer- Neldel rule. In such experiments, changing composition of the glassy sample changes the activation energy. In the present work we have changed ∆E by applying high electric fields. It is shown that Meyer- Neldel rule is obeyed in this case also where composition of the material is not changed. This indicates that this rule is more general in chalcogenide glasses and is not due to changes in certain parameters on changing composition