Improvement of the electrical properties of Se3Te1 thin films by In additions

The electronic and photoconductivity properties of semiconducting chalcogenide glasses have been largely stimulated by attractive micro-electronic device applications. The present paper aims to study the effect of In additions on the steady state and transient photoconductivity of amorphous Inx(Se3Te1)100 − x (0 ≤ x ≤ 10 at.%) chalcogenide films. It was found that, the Indium additions lead to the decrease of both the activation energies (ΔEdc in the dark and ΔEph for the photoelectrical conduction) and the optical band gap Eg that improved the electrical properties of these films. The photoconductivity increases while photosensitivity changes from 8.73 to 7.18 with the increase of In content. The exponential dependence of photocurrent on the light intensity suggests that, the recombination mechanism in these films is due to bimolecular recombination. The transient photoconductivity measurements stated that, the carrier lifetime decreased by the increase of the light intensity and In content. The obtained results were discussed in terms of the width of localized states (Mott and Davis model) and the chemical-bond approach.

► In this paper Inx(Se3Te1)100 − x thin films were prepared by thermal evaporation.
► dc- and ac-photoconductivity was measured in the temperature range of 300–400 K.
► The photocurrent exceeds by at least seven fold times than the dark current.
► ac-and dc-photoconductivity was studied at different electric fields and light intensities.
► The optical band gap were found to decrease with the increase in Indium content.