Synthesis and Nanostructures of Metal Selenide Precursors for Cu(In,Ga)Se₂ Thin-Film Solar Cells

A nanoink solution-based process was developed as a low-costing method for the fabrication of Cu(In,Ga)Se₂ (CIGSe) thin-film photovoltaic cells. The sonochemical synthesis of CIGSe nanocrystals of the nanoink through step-by-step mixing of the reactants was investigated. To achieve the ideal stoichiometry of Cu(In_0.7Ga_0.3)Se₂ to tune the bandgap and to fabricate high-efficiency photovoltaic cells, the synthetic parameters, the concentration of hydrazine, and the amount used of the gallium precursor were investigated. As the hydrazine concentration increased, gallium loss was observed in the CIGSe product. The gallium content in the reactant mixture strongly affected the metal stoichiometry of the prepared CIGSe nanocrystals. The nanoink solution based fabrication of thin-film photovoltaic cells was also explored, and the resulting device showed a conversion efficiency of 5.17. GaGa over nanoparticles: Variation of the gallium concentration in Cu(In_0.7Ga_0.3)Se₂ nanoparticles (CIGSe NPs is investigated by sonochemical synthesis in hydrazine/ethylene glycol solution. The CIGSe device prepared by the nanoink solution based process exhibits a conversion efficiency of 5.17.