Characterization of thermally evaporated AgGaTe2 films grown on KCl substrates

摘要

Silver gallium telluride (AgGaTe2) films have been grown by thermal evaporation technique onto the KCl substrates kept at different temperatures (483–563 K) in a vacuum of 1.3 × 10−3Pa. The experimental conditions were optimised to obtain better crystallinity of the films. The films so prepared have been studied for their structural, optical and electrical properties. Observations reveal that the crystallinity of the films increases with increase in substrate temperature. Average crystallite size of 0.2–0.5 μm has been observed in case of films deposited at 563 K. Analysis of optical spectra of the films in the range 300–1100 nm show an allowed direct transition near the fundamental absorption edge (E g1) in addition to a transition originating from crystal field split levels (E g2). It has been observed that the carrier concentration and Hall mobility of films increases with increase in substrate temperature.