A non-platinum counter electrode, MnN x /C, for dye-sensitized solar cell applications

Abstract

A non-platinum metal catalyst, MnN x /C was synthesized via the high-pressure pyrolysis route. The combination of X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) studies indicated the presence of Mn in +2 oxidation state surrounded by four N atoms. The peak-to-peak separation (ΔE p ) of the more negative peak pair observed for I 3 − /I − redox couple over MnN x /C catalyst was 20 mV lower than that of the Pt catalyst, indicating high reversibility of the redox couple over MnN x /C catalyst. The charge transfer resistance of the MnN x /C electrode, as measured by the impedance spectroscopy, is ∼ 2 Ω higher than that of Pt, which resulted slightly lower short circuit current (Jsc) value for MnN x /C over Pt, however the fill factor (FF) and power conversion efficiency (PCE) values of MnN x /C was slightly higher and comparable to that of Pt respectively. Hence; replacing Pt with MnN x /C would decrease the cost of DSSCs. © 2016 Elsevier B.V.