Abstract
We report the fabrication of copper zinc tin sulfide, Cu2ZnSnS4, nanoparticles by a solvothermal method. We synthesized a polymer matrix-based organic hybrid photovoltaic active layer using poly (3-hexyle thiophene) (P3HT) [6,6]: phenyl-C61-butyric-acid-methyl-ester (PCBM) and Cu2Zn SnS4 (CZTS) nanoparticles (NPs). The objective of this exploration is to verify the performance dependence of polymeric solar cells on the concentration of CZTS NPs. The active layers were doped with different concentrations of CZTS NPs (0.2, 0.4, 0.6, 0.8 mg/mL) in the P3HT: PCBM polymer. The CZTS NPs and the prepared polymer active layer were characterized by different characterization methods such as: X-ray diffraction (XRD), UV-Visible spectrophotometer, transmission electron microscopy (TEM), and Fourier Transform Infrared (FTIR), Atomic force microscopy (AFM). The hybrid photovoltaic active layer was enhanced by doping with CZTS NPs, which led to an improved homogeneous structure and incremental increases in the light absorption and electrical conductivity. X-ray diffraction (XRD) results showed that the orientation of the P3HT crystallites was affected by the blend ratio within the block polymer films. A red-shift of the FTIR results was observed as the doping concentration increased. The root-mean-square value of the samples decreased from 10.95 to 0.68 nm as the CZTS NPs concentration increased, indicating improved surface roughness. The optical properties indicated the relationship between light absorption and the morphology of the active layer. Polymer solar cells with the structure ITO/ZnO/P3HT: PCBM: CZTSNPs/Ag were fabricated. The power efficiency obtained was 3.11%, with a short-circuit current density (Jsc) of 11 mA/cm(2), an open-circuit voltage (Voc) of 412 mV, and a fill factor of 68.7%. These results show the role of CZTS NPs in the development of high-efficiency P3HT:PCBM polymer solar cells.