Enhanced Dye-Sensitized Solar Cell Efficiency by Insertion of a H3PW12O40 Layer Between the Transparent Conductive Oxide Layer and the Compact TiO2 Layer

In this paper, H3PW12O40 (PW12) was deposited as an interfacial layer between transparent conductive oxide layer and compact TiO2 layer of a dye-sensitized solar cell. The films were characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy to gain an insight into the morphology and composition. The photovoltaic performance was evaluated by current-voltage curve. The effect of the interfacial layer was investigated by electrochemical impedance spectroscopy, open-circuit voltage decay measurement and Mott-Schottky measurement. The results showed that the introduced interfacial layer could reduce the recombination of the electrons, resulting in longer electron lifetime. The solar cells with H3PW12O40 exhibited the conversion efficiency of 9.3%, which was higher than that of DSSCs without TiO2 compact layer and PW12 interfacial layer.