Amphiphilic Z907 dye grafted ZnS/rGO and Zn_1−XCd_XS/rGO decorated nano-hybrid structures: Synthesis, characterization and applications in solid state dye sensitized solar cells

In this research work, bare ZnS, ZnS reduced graphene oxide (ZnS/rGO) and Cadmium doped ZnS reduced graphene oxide (Zn_1−XCd_XS/rGO) decorated nanocomposites were successfully synthesized through facile coprecipitation method. Optical and morphological analysis of these synthesized nanomaterials were done by using UV-Visible, florescence spectroscopy, X-Ray diffraction spectroscopy (XRD), Field emission scanning electron microscopy (FESEM), Elemental dispersive X-Ray analysis (EDX), Transmission electron microscopy (TEM), Fourier transform infra-red (FT-IR) and Raman spectroscopy. The band gap values were calculated from the optical absorption spectra. The study reveals that the band gap of ZnS (3.96 eV) was effectively tuned up to 2.99 eV by coupling with reduced graphene oxide. The phase purity, crystalline nature,morphology, functional groups detection, elemental composition of the samples were confirmed through XRD, FESEM,TEM,FTIR and EDX respectively. The Z907 dye grafted nanomaterials were combined P3HT (hole conducting polymer) to make a photoactive blend for dye sensitized solar cell. The fabricated cells were then investigated by using current –voltage (I-V) measurements. I-V measurements revealed that the photoconductive ability of ZnS nanoparticles has been significantly enhanced on the formation of its ZnS/rGO and Zn_1−XCd_XS/rGO decorated nanocomposites. Boost in efficiency of about 64% and 83% in comparison to reference device has been observed for Ru/ZnS/rGO-P3HT (0.466%) and Ru/Zn_1−XCd_XS/rGO-P3HT (0.522%). Enhanced Jsc and Voc values of these synthesized composites presented them as ground materials for further research by interface engineering to enhance their efficiency in SSDSSCs.