Electronic conductivity of AgI using D.C. polarization and charge transfer techniques

Abstract

A Study of electronic conductivity using the d.c. polarization technique has been carried out in α and β-AgI which shows the former is a hole and the latter an electron conductor. Activation energies of undoped and Cu-doped single crystals and polycrystalline β-AgI were found to be 0.46 eV, 0.34 eV and 0.44 eV respectively and can be related to electron trap depths. The electron transference number ( σ θ σ t ) for polycrystalline β-AgI was found to be 0.008 at 306 K. The activation energy for hole conduction in α-AgI was determined to be 0.97 eV in agreement with previous XPS studies. Transient measurements have also been conducted using the charge transfer technique in double cells of polycrystalline β-AgI. The carrier concentration C θ and electron mobility μ θ, have thus been estimated to be 1.8 × 10 15 cm 3 and 5.14 × 10 −5 cm 2 V −sec. respectively at 306 K, while the double layer capacitance was 0.496 μF cm 2 .