Abstract
Tri-functional Nb 2 O 5 nano-islands are deposited on indium tin oxide (ITO) transparent conductive layer on a plastic sheet (ITO PEN) as the anode substrate for a dye-sensitized solar cell by spin-coating a niobium precursor solution and heating at 150°C for 10 min. The films are characterized by means of time of flight secondary ion mass spectrometry (TOF/SIMS), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), small angle X-ray diffraction (SAXRD), electrochemical impedance spectroscopy (EIS), four-probe meter and currentevoltage curves. It was found that the Nb 2 O 5 coating exhibits at least three functions, including suppressing interfacial recombination, improving TiO 2 film adhesion and lowering sheet resistance of the ITO PEN film; these functions are all beneficial to photovoltaic performance in a dye-sensitized solar cell. Finally, a plastic dye-sensitized solar cell with this Nb 2 O 5 -treated photoanode was fabricated, and a remarkable improvement of power conversion efficiency (PCE), from 5.19% to 5.81% was demonstrated. © 2013 Elsevier B.V. All rights reserved.