Photoconductivity of amorphous As2S8 chalcogenide film under bandgap light irradiation

The photoconductivity of amorphous As2S8 chalcogenide film under the irradiation of bandgap light is investigated. In the temperature range 300–350 K, the dark conductivity and photoconductivity of the annealed As2S8 film increase with the temperature, and the dependence of the both on temperature shows that the conduction in As2S8 film is an activated process having single activation energy. Under the irradiation of bandgap light, the photocurrents of the annealed and illuminated As2S8 film increase with the irradiation intensity, and their difference indicates the existence of the light-soaked effect. Meanwhile, the photoconductivity degradation during the irradiation and the photocurrent decay after stopping the irradiation are observed. By adding the irradiation of the sub-bandgap light, the enhancement of photoinduced voltage occurs.