Electrodeposition of CuInSe2 thin films

M. VALDÉS; M. VÁZQUEZ

Electrodeposition: Properties, Processes and Applications

Nova Science Publishers, Inc.

Año: 2011;

Copper indium chalcogenides are materials under permanent investigation due to their potential use for photovoltaic applications, given that they show a high absorption coefficient, coupled to a band gap energy value that matches that of the solar radiation. Many techniques have been reported to prepare CuInSe2 (CISe) as a thin film. Among them, electrodeposition presents many advantages: it is cost-effective, mainly because it does not require high vacuum, it may be used to copy intricate geometries while being applied even on top of flexible substrates and it can be scale-up into industrial production. CuInSe2 (CISe) thin films have been prepared by electrodeposition from a single bath on top of conductive glass as well as on conductive glass coated with thin layers of TiO2 and In2S3. Potentiostatic and pulsed electrodeposition produced films with different properties. The electrodeposition conditions were decided after carrying out cyclic voltammetry in acidic electrolytes. CISe precursors films need to be subjected to different thermal treatments to enhance the crystallinity of the deposit. The presence of sulfur vapor during annealing leads to substantial changes in the composition of the chalcogenide. The crystallinity, morphology and stoichiometry of the annealed films is characterized by XRD, microRaman spectroscopy and SEM/ coupled with Energy dispersive scanning (EDS). Etching the films in KCN solution is a key step, enabling a final adjustment in the stoichiometry. Photoelectrochemical measurements are employed to obtain semiconductor properties of the CISe films and to elucidate the influence of the post-deposition treatments.