Fabrication of CIGSSe Thin Film Solar Cells with Colloidal Synthesized CuIn0.7Ga0.3S2 Nanocrystals

Quaternary colloidal CuIn0.7Ga0.3S2 nanocrystals were synthesized by hot injection method using oleylamine as single solvent. The structure, morphology and optical absorption properties of assynthesized CuIn0.7Ga0.3S2 nanocrystals were characterized in detail using X-ray powder diffraction, transmission electron microscopy and UV-vis spectrometry. The as-fabricated CIGSSe thin film was obtained by spin-casting as-synthesized colloidal CuIn0.7Ga0.3S2 nanocrystals after selenization. The classical pn heterojunction CIGSSe/CdS thin film solar cells displayed the 6.18% power conversion efficiency under AM1.5G illumination.