Fabrication of copper–indium–gallium–diselenide absorber layer by quaternary-alloy nanoparticles for solar cell applications

Copper–indium–gallium–diselenide (CIGS) thin films were fabricated using precursor nanoparticle-ink and sintering technology. The precursor uses quaternary compound composition ratios of Cu/(In + Ga) = 0.95, Ga/(In + Ga) = 0.39, and Se/(Cu + In + Ga) = 0.75, respectively. The nanoparticles were fabricated by a rotary ball milling technique. After milling, the agglomerated CIGS powder to a particle size smaller than 100 nm. The nanoparticle-ink was fabricated by mixture of CIGS nanoparticles, solution, and organic polymer. Crystallographic, morphological, stoichiometric, and photovoltaic properties of films were obtained by sintering the precursor CIGS sample in a non-vacuum environment with selenization. Analytical results indicate that the CIGS absorption layer prepared with a nanoparticle-ink polymer, through sintering, has a chalcopyrite structure and favorable compositions. In this sample, the mole ratio of Cu:In:Ga:Se is equal to 0.95:0.69:0.38:1.99, and related ratios of Ga/(In + Ga) and Cu/(In + Ga) are 0.35 and 0.89, respectively. Analysis of a performance of the obtained solar cell under standard air mass 1.5 global illumination revealed a conversion efficiency of 2.392%.