Deposition potential effect on the proprieties of CuInSe2 thin films

Bouraiou Assia*, M.S. Aida

Thin films and interfaces laboratory, Physics

Department, Mentouri university, Constantine Algeria

E-mail: a_bouraiou@yahoo.fr

ABSTRACT

The purpose of this work is to deposit the CuInSe₂ films on the ITO substrate by electrodeposition technique using a simplified two electrodes system and to investigate the effect of the deposition potential on the fundamental properties of the resulting films. The electrolyte bath used for the films elaboration consisted of 10 mM copper chloride (CuCl₂), 40 mM indium chloride (InCl₃) and 20 mM selenium oxide (SeO₂) dissolved in de-ionized water. The deposition potential is varied between 4 and 8 Volts. The as deposited films were annealed under argon atmosphere at 300 °C during 30 min. The structural, morphological, and electrical properties were characterized respectively by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrical resistivity measurements. The optical band gap of samples was estimated using the optical absorption technique.

After annealing, the XRD spectra show diffraction peaks corresponding to the single-phase chalcopyrite CuInSe₂ with (112) as main reflection. The SEM images reveal a homogeneous surface. We have found also that the E_g of the resulting films is less than the optimum value for the terrestrial solar spectrum; therefore the prepared samples can be used as an absorber layer in the fabrication of thin film solar cells.

Keywords: CuInSe₂, Electrochemical deposition, deposition potential, Thin films, Photovoltaic.

Corresponding author contact: Thin films and interfaces laboratory physics department, Mentouri University, Constantine, 25000  Algeria, FAX no.: 21331614711, Tel.: 21331614711