Nanostructured TiO2 modified with acetohydrazide zinc porphyrin well-arrays for supramolecular solar cells

Abstract

In this work, employing the metal-mediated assembling strategy for organizing acetohydrazide zinc porphyrin (ZnP) and different organic acid (Ai) ligands on the nanostructured TiO2 electrode surfaces have been prepared, wherein the ZnP and Ai units are bound by a series of differently bivalent metal ions (M, M=Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+ and Hg2+), resulting in a ZnP–M–Ai assembled approach. The photovoltaic performances of these assemblies-sensitized solar cells were performed under irradiance of 100mWcm−2 AM 1.5G sunlight. A significantly improved conversion efficiency of ZnP–Mn–A5 and ZnP–Cd–A5 devices occurs, indicating well-ordered arrangements of ZnP molecules on the TiO2 electrode surfaces for ZnP–Mn–A5 and ZnP–Cd–A5, where A5 is a pyridine–monocarboxylic acid ligand bearing longer arm. The results were also verified by the HOMO–LUMO gaps, UV–vis and fluorescence spectra.