Poole-Frenkel photoconductivity in amorphous Se75Te20Sb5 thin films

In many amorphous and liquid semiconductors and many other class of materials, pre-exponential factor of electrical conductivity σ₀ is found to increase exponentially with activation energy ΔE according to Meyer-Neldel rule. This rule is generally verified by selecting different compositions of different ΔE in a given class of materials. In the present paper, we report the investigation of Meyer-Neldel rule (MN rule) for the pre-exponential factor (σ _ph )₀ and activation energy of (ΔE _ph ) photoconductivity in amorphous thin films of Se₇₅Te₂₀Sb₅ for high field conduction. The photoconduction was found to be ohmic at low fields and of Poole-Frenkel type at high fields. In the present work we have changed ΔE _ph by applying high electric fields.