Iron Pyrite Thin Film Counter Electrodes for Dye-Sensitized Solar Cells: High Efficiency for Iodine and Cobalt Redox Electrolyte Cells

Abstract

Iron pyrite has been the material of interest in the solar community due to its optical properties and abundance. However, the progress is marred due to the lack of control on the surface and intrinsic chemistry of pyrite. In this report, we show iron pyrite as an efficient counter electrode (CE) material alternative to the conventional Pt and poly(3,4-ethylenedioxythiophene (PEDOT) CEs in dye-sensitized solar cells (DSSCs). Pyrite film CEs prepared by spray pyrolysis are utilized in I3(-)/I(-) and Co(III)/Co(II) electrolyte-mediated DSSCs. From cyclic voltammetry and impedance spectroscopy studies, the catalytic activity is found to be comparable with that of Pt and PEDOT in I3(-)/I(-) and Co(III)/Co(II) electrolyte, respectively. With the I3(-)/I(-) electrolyte, photoconversion efficiency is found to be 8.0% for the pyrite CE and 7.5% for Pt, whereas with Co(III)/Co(II) redox DSSCs, efficiency is found to be the same for both pyrite and PEDOT (6.3%). The excellent performance of the pyrite CE in both the systems makes it a distinctive choice among the various CE materials studied.

Scientific and Technological Assessment of Iron Pyrite for Use in Solar Devices

“…(g) XRD pattern and (h)Raman spectra of as-sprayed and sulfurized films at different temperatures. [38] Reprinted with permission from Ref. [31].C opyright2 014 American ChemicalS ociety.…”

“…Recently,w ee valuated iron pyrite to replace Pt and C counter electrodes. [38] Its transition-metal chemistry,F e-S co- [8] Reprintedwithpermission from Ref. [8].C opyright 2016 AmericanC hemical Society.…”

“…[9,33,34] Interestingly,ap yrite-marcasite mixed-phase thin film performed better than ap ure pyrite film in ap hotoelectrochemical cell, invalidating the belief that marcasite is detrimental to photon conversion.T his performance of the mixed phase film was attributed to improved charge separation. Despite the setback in the solar-cell application,i ron pyrite has been evaluated in many othero ptical devices such as high-responsivity photodetectors,n ear-IR photodiodes, [33,35,36] catalyst in dye-sensitizeds olar cells (DSSCs), [37,38] photoconductors, [39] or bulk-heterojunction inorganic-organic hybrids olar cells, [40] where appropriate post treatments and custom-designed device architecturesw ere successfully employed. This illustrates that the potential of the material can be harnessed by appropriate processing and device engineering for specific applications other than purely for light absorption.…”

Facile and quick preparation of carbon nanohorn-based counter electrodes for efficient dye-sensitized solar cells

“…[4][5][6] There have been several attempts to substitute Pt, while still maintaining a good performance. Firstly, transition metal complexes (TMC) are widely used due to activities similar to that of Pt.…”

“…3 The usage of rare metals including platinum (Pt) in counter electrodes (CE) raises the overall production costs, and, as such, constitutes a major bottleneck in terms of its introduction into the market. [4][5][6] There have been several attempts to substitute Pt, while still maintaining a good performance. Firstly, transition metal complexes (TMC) are widely used due to activities similar to that of Pt.…”