Laser-induced synthesis of thin CuInSe2 films

Abstract Thin CuInSe 2 films were synthesized by laser irradiation of Cu/In/Se sandwiches in an atomic ratio of 1:1:2. The synthesized free-standing films ( i.e. supported on transmission electron microscope grids) were shown to have the tetragonal structure characteristic of the ternary compound; a similar result was obtained for films supported on glass substrates. No evidence of other phases (binary or elemental) was obtained for any of the irradiated films. The optical absorbance characteristics of a uniform transformation region indicate the presence of a direct optical band gap of 0.9±0.1 eV. The crystallites obtained on irradiation can be very large (20 μm in free-standing films). The CuInSe 2 compound is also laser synthesized in some non-stoichiometric free-standing films.