Photoconductive and electrical transport properties of AgInSe2 thin films prepared by co-evaporation

This work presents results regarding the influence of preparation conditions on the photoconductive and electrical transport properties of AgInSe2 (AISe) films, grown by co-evaporation of precursors in a two-stage process. For this, the AISe films were investigated by transient and steady-state photocurrent, conductivity and Hall voltage measurements. Measurements of conductivity as a function of temperature, carried out in the range between 90 and 600 K, revealed that the electrical transport in AISe films is affected by two different mechanisms. At temperatures greater than 350 K, the conductivity is predominantly affected by hole transport in extended states of the valence band, whereas at temperatures below 250 K the conductivity is mainly determined by the variable range hopping (VRH) transport mechanism. The results also revealed that the growth temperature and chemical composition critically affect the recombination processes and the photosensitivity of the AISe films. (C) 2010 Elsevier B.V. All rights reserved.