Fabrication of Cu(In,Ga)Se2 Thin Film by Selenization of Stacked Elemental Layer with Solid Selenium

Abstract

Cu(In,Ga)Se2 thin films were prepared using the classical two-step process approach. In the first step, the metallic precursors were deposited on the soda-lime glass substrates by electron-beam evaporation following the Cu/In/Ga... sequence. The selenization, called the second step, was produced in a rapid thermal processor. This process performed under nitrogen atmosphere of 200 Torr at 200°C for 5 minutes followed by 500°C for 3 minutes. The device quality of CIGS film, with the atomic ratios of Cu/(In+Ga) of 0.90 and Ga/(In+Ga) of 0.26, was obtained when the Cu/In/Ga metallic layer had thinness ratio of 900 Aå/600 Aå /200 Aå. The CIGS film with homogeneous and dense surface morphology with large grain size (~ 2 μm) was formed.