Fabrication and characterisation of CuInSe2/Si(1 0 0) thin films by the stacked elemental layer (SEL) technique

Thin films of (Cu/In/Se) were fabricated by evaporated elemental layers of Cu, In and Se on Si (1 0 0) and on glass substrates at TS = 250 °C. Films with phase chalcopyrite structure and strong (1 1 2) preferred orientation were produced. EDX showed uniform compositional properties of the films over a substrate area of 1 cm2. The optical energy band gap of 0.984 eV was obtained and photoluminescence measurements have been carried out in as-deposited polycrystalline Cu/In/Se thin films deposited onto (1 0 0) oriented Si wafers doped with 1015 cm−3 of boron. The PL spectra of CuInSe2 show emission peaks at 0.87 eV ranging from 0.75 to 0.98 eV. The broad emission band is ascribed to donor–acceptor pair (DAP) transition.