Investigation of optoelectronic properties by producing tio2 mesoporous / zno nanotel based tandem (layered) nano semiconductor and producing dye-sensi̇ti̇zed solar cell

Dye Sensitized Solar Cell were produced with innovative design and a new method which is growth of one dimensional (1D) ZnO nanowire within TiO2 mesoposous on graphene substrate. Standard TCO (Transparent Conductive Oxide) problem in DSSC which is limiting photo-electron conversion efficiency were removed with monolayer graphene synthesis on FTO (F: SnO2) substrate. Solar Conversion Efficiency was investigated by growth of TiO2 mesoporous/ZnO nanowire tandem nano-semiconductors on graphene covered substrate as different conventional DSSC and it was compared with FTO based substrate. Structural, optical and thermal characterization were carried out by using SEM, XRD, EDAX, DTG, TG, PL and UV-Vis absorption spectroscopy. Solar conversion efficiency and quantum efficiency (QE) were examined by J-V and IPCE measurements. XRD characterization shows that the all diffraction peaks of the tandem nanostructures films can be well indexed to a mixture of hexagonal wurtzite ZnO and anatase TiO2 structures. The UV–Visible absorbance spectrum indicates that the tandem nanostructures based on TiO2 mesoporous/ZnO nanowire arrays have 3.13 eV band gap energy. Photovoltaic performance of Graphene/TiO2/ZnO hybrid semiconductors, FTO/TiO2/ZnO, pure FTO/TiO2 and pure FTO/ZnO were compared each other and the most useful materials as substrate and photo anode were determined. Solar conversion efficiency of Graphene/TiO2/ZnO hybrid based DSSC were obtained as ƞ= %8.7,Jsc= 21.3 mA/cm3, Voc=0.78V and FF=0.53 and it was shown that graphene based DSSC have much higher solar conversion efficiency 30% FTO/TiO2/ZnO. As a result, electron transport increase to counter electrode when graphene covered on substrate, In addition, high surface area were obtained on substrate by growth TiO2/ZnO hybrid structures which enable direct electron transfer without recombination.