Influence of RF Magnetron Sputtering Condition on the ZnO Passivating Layer for Dye-sensitized Solar Cells

Abstract

Dye-sensitized solar cells have a FTO/TiO2/Dye/Electrode/Pt counter electrode structure, yet more than a 10% electron loss occurs at each interface. A passivating layer between the TiO2/FTO glass interface can prevent this loss of electrons. In theory, ZnO has excellent electron collecting capabilities and a 3.4 eV band gap, which suppresses electron mobility. FTO glass was coated with ZnO thin films by RF-magnetron sputtering; each film was deposited under different O2:Ar ratios and RF-gun power. The optical transmittance of the ZnO thin film depends on the thickness and morphology of ZnO. The conversion efficiency was measured with the maximum value of 5.22% at an Ar:O2 ratio of 1:1 and RF-gun power of 80 W, due to effective prevention of the electron recombination into electrolytes. © 2013 KIEEME. All rights reserved.