Preparation of multiband structure with Cu2Se/Ga3Se2/In3Se2 thin films by thermal evaporation technique for maximal solar spectrum utilization. (October 2016)

• Record Type: Journal Article
• Authors: Mohan, A.; Rajesh, S.; Gopalakrishnan, M.
• Is Part Of: Superlattices and microstructures. Volume 98(2016)
• Page Start: 46
• Page End: 53
• Publication Date: 2016-10
• Subjects: Multiband -- Stacking -- Composites -- Annealing -- Full solar spectrum utilization; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2016.08.006
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: The paper investigates and discusses the formation of multiband structure through the Cu2 Se-Ga3 Se-In3 Se2 thin films for maximal solar spectrum utilization. Stacking different semiconductor materials with various band gaps were done by successive evaporation method. Based on the band gap values the layers are arranged (low to high bandgap from the substrate). The XRD results exhibits the formation of CIGS composites through this successive evaporation of Cu2 Se/Ga3 Se/In3 Se2 and treating then with temperature. Scanning Electron Microscope images shows improved crystallinity with the reduction in the larger grain boundary scattering after annealing. Optical spectra shows the stronger absorption in an UV–Visible region and higher transmission in the infrared and near infrared region. The optical band gap values calculated for as prepared films is 2.20 eV and the band gap was split into 1.62, 1.92 eV and 2.27eV for annealed samples. This multiband structures are much needed to utilize the full solar spectrum. Graphical abstract: Highlights: Cu2 Se/Ga3 Se2 /In3 Se2 multiband structure deposited by thermal evaporation technique. CuSe-GaSe-InSe composite formation through annealing. TEM, XRD and PL studies confirms the composite formation.