CUIn1-xGaxSe2 （CIGS） films were prepared by a two-stage method, in which Cu-In-Ga metallic precursors were firstly deposited on unheated Mo-coated soda lime glass substrates by direct current sputtering CuGa （20%Ga） and radio frequency sputtering In targets in an Ar atmosphere, followed by selenization at 520 ℃ for 40 min in Se vapor. By adjusting the sputtering thickness ratio of surface CuGa （20%Ga） and bottom CuGa （20%Ga） alloy layers in metal precursor, different CIGS thin films were fabricated. Through X-ray diffraction spectra, Raman spectra, local energy dispersive spectrometer, planar- and cross- sectional views of scanning electron microscopy measurements, it revealed that the CIGS thin films from selenization of metal precursor with CuGa：In：CuGa thickness ratio of 7：20：3 （sample-2-se） was of chalcopyrite structure with the preferred （112） orientation, and the grains sizes ranged from 0.5 μm to 2 μm, and sample-2-se had no binary compound phase of In-Se and order defect compound phase. Consequently, the results of illuminated current- voltage curve and quantum efficiency measurements showed that the CIGS film device made from sample-2-se had relative higher photo-electric conversion efficiency （3.59%） and good spectrum response.
Copper indium diselenide nanorod arrays were electrodeposited on tungsten/silicon rigid substrates using porous anodic alumina as growth template. The porous anodic alumina templates were prepared by anodizing aluminum films which were sputtered onto the tungsten/silicon substrates. A selective chemical etching was used to penetrate the barrier layer at the bottom of the alumina channels before electrodeposition, which enables direct electrical and chemical contact with the underside substrate electrode. The as-deposited samples were annealed at 450 ℃ in vacuum. Scanning electron microscopy revealed that the nanorods were dense and compact with diameter of about 100 nm, length of approximate 1 um, and the aspect ratio of 10. X-ray diffraction, micro-Raman spectroscopy, and high resolution transmission electron microscopy showed that chalcopyrite polycrystalline structure and high purity CuInSe2 nanorods were obtained. The grain size was large in the rod axial direction. Energy-dispersive X-ray spectroscopy showed the composition was nearly stoichiometric. The energy band gap of this nanorod arrays was analyzed by fundamental absorption spectrum and was evaluated to be 0.96 eV.
CuInSe2 （CIS） films with good crystalline quality were synthesized by electrodeposition followed by annealing in Se vapor at 530 ℃. The morphology, composition, crystal structure, optical and electrical properties of the CIS films were investigated by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, Raman spectroscopy, UV-VISNIR spectroscopy, and admittance spectroscopy. The results revealed that the annealed CIS films had chalcopyrite structure and consisted of relatively large grains in the range of 500-1000 nm and single grain of films extend usually through the whole film thickness. The band gap of CIS films was 0.98 eV and carrier concentration was in the order of 1016 cm-3 after etching the Cu-Se compounds on the film surface. Solar cells with the structure of AZO/i-ZnO/CdS/CIS/Mo/glass were fabricated. Current density vs. voltage test under standard reported condition showed the solar cells with an area of 0.2 cm2 had a conversion efficiency of 0.96%. The underlying physics was also discussed.
