Se-loss-induced CIS Thin Films in RTA Process after Co-sputtering Using CuSe₂and InSe₂Targets

Abstract

-Chalcopyrite CuInSe 2 (CIS) thin films were prepared without Se-/ S-containing gas by co-sputtering using CuSe 2 and InSe 2 selenide-targets and rapid thermal annealing. The grain size increased to a maximum of 54.68 nm with a predominant (112) plane. The tetragonal distortion parameter η decreased and the inter-planar spacing d (112) increased in the RTA-treated CIS thin films annealed at a 400°C, which indicates better crystal quality. The increased carrier concentration of RTA-treated p-type CIS thin films led to a decrease in resistivity due to an increase in Cu composition at annealing temperatures ≥ 350°C. The optical band gap energy (E g ) of CIS thin films decreased to 1.127 eV in RTA-treated CIS thin films annealed at 400°C due to the improved crystallinity, elevated carrier concentration and decreased In composition.