CHARACTERIZATION OF CuIn_1-xGa_xSe₂ THIN FILM

 SOLAR CELL APPLICATIONS

N. Benslim^a, S. Mehdaoui_a, O. Aissaoui^a, L. Bechiri^a, M. Benabdeslem^a, A. Otmani^b, X.Portier^c.

^aLaboratoire d’Etude de Surfaces et Interfaces de la Matière Solide (LESIMS), Département de Physique, Faculté des Sciences, Université Badji Mokhta, BP 12 Sidi Amar- Annaba 23000, Algérie

E-mail : n_eddinebenslim@yahoo.fr

^bLaboratoire de Recherche en Physico-Chimie des Surfaces et Interfaces (LRPCSI), faculté des Sciences Université de Skikda -BP26 route El-Hadaek (21000) Skikda

^c Cimap-ENSICAEN, Université, 6 Boulevard du Marechal Juin, 14050 Caen, France

Abstract

CuIn_xGa_1-xSe₂ with (0£ x £1) thin films is investigated for their application as absorber layer material for solar cells. Chalcopyrite type CuIn_xGa_1-xSe₂ powders were successfully synthesized by mechanical alloying from the elemental powders of Cu,In,Ga and Se. Thin films were deposited on corning glass substrates at 300 °C by thermal evaporation method.  The X-ray diffraction studies revealed that all the deposited films and powders are polycrystalline in nature and exhibiting chalcopyrite structure. The crystallites were found to have a preferred orientation along the (112) direction.  Based on the XRD data, the lattice parameters and grain sizes were calculated.  The composition of the chemical constituents present in the deposited CuIn_xGa_1-xSe₂ thin films has been determined using energy dispersive X-ray analysis (EDAX). The transmittance characteristics of the samples have been studied using double beam spectrophotometer in the wave length range 400-2400 nm.  The absorption coefficient has been found to be very high and is of the order of 10⁴-10⁵ cm^-1.  The band gap E_g, estimated from optical absorption data, was between 1.04-1.65 eV.

Keywords: Thin films, Chalcopyrite, Solar cells.