Efficient Dye-Sensitized Solar Cells with Catalytic Multiwall Carbon Nanotube Counter Electrodes

Abstract

We report the successful application of multiwall carbon nanotubes (CNTs) as electrocatalysts for triiodide reduction in a dye-sensitized solar cell (DSSC). Defect-rich edge planes of bamboolike-structure multiwall CNTs facilitate the electron-transfer kinetics at the counter electrode-electrolyte interface, resulting in low charge-transfer resistance and an improved fill factor. In combination with a dye-sensitized TiO2 photoanode and an organic liquid electrolyte, a multiwall CNT counter-electrode DSSC shows 7.7% energy conversion efficiency under 1 sun illumination (100 mW/cm(2), air mass 1.5 G). The short-term stability test at moderate conditions confirms the robustness of CNT counter-electrode DSSCs.

Photoelectrochemical Cell Study on Closely Arranged Vertical Nanorod Bundles of CdSe and Zn doped CdSe Films

“…Because, CdSe has relatively more voids and point defect than in CdSe:Zn and this shall decrease the recombination rate in CdSe:Zn than in CdSe nanorod bundled films. 30,31 Impedance spectra. Electrochemical impedance spectroscopy (EIS) is a very powerful tool for the analysis of changes in interfacial capacitance or resistance occurring at conductive or semiconductive surfaces.…”

Carbon Nanostructures as Low Cost Counter Electrode for Dye-Sensitized Solar Cells

“…It was found that IPCE of carbon nanofiber cells was slightly smaller than that of Pt devices in the 550-750 nm spectral range, consistent with the relatively lower J sc . This was probably caused by that the Pt counter electrode can reflect unabsorbed light back to TiO 2 photoanode for re-absorption by the dye (Fang et al 2004;Lee et al 2009;Wang et al 2009). However, carbon nanofiber counter electrode cannot reflect such unabsorbed light.…”

“…Recently, various carbonaceous materials including graphite, carbon black, and carbon nanotubes have been studied as a low cost replacement for Pt as an electrocatalyst for reduction of I 3  ions (Kay & Gratzel 1996;Burnside et al 2000;Suzuki et al 2003;Murakami et al 2006;Ramasamy et al 2007;Fan et al 2008;Hinsch et al 2008;Joshi et al 2009;Lee et al 2009;Skupien et al 2009;Calandra et al 2010). The carbonaceous materials are plentiful, inexpensive, and also exhibit high resistivity to corrosion (Ramasamy et al 2007).…”

Pulsed-laser-ablation based nanodecoration of multi-wall-carbon nanotubes by Co–Ni nanoparticles for dye-sensitized solar cell counter electrode applications

“…This behaviour may be attributed to the degradation of Pt film and to the consequent loss of adhesion between Pt and its underlying conductive glass substrate. Carbon nanotubes are, moreover, optimal catalysts for the redox reaction of the electrolyte solution [14][15][16]. Their high surface area and the presence of defects sites on their functionalized surface enhance the electron transfer and chemical reactivity of these Pt-free CEs.…”

“…A variety of chemical and physical methods, including hydrothermal methods [27][28][29][30][31][32], pyrolysis [18], electrodeposition [20], electrospinning method [14], and calcination [22], have been used for the synthesis of metal NPs and/or their deposition onto several carbon-based materials, such as carbon nanotubes [18,20,21], carbon fibres [27,31] and graphene [28,29], but most of these techniques require chemical precursors, generally high processing temperatures, long reaction/deposition times (several hours), and most often post-synthesis treatments with strong acids to remove metal residues. As an alternative to these chemical synthesis routes, pulsed-laser deposition (PLD) is a versatile physical method that has been shown to be highly effective for the in situ decoration of different substrates (including CNTs or TiO 2 nanorods) by highly pure metallic or semiconducting nanoparticles [33][34][35][36][37][38] with a fair control over their particle size, surface coverage and crystallinity.…”