Novel Dye-Sensitized Solar Cell Architecture Using TiO₂-Coated Vertically Aligned Carbon Nanofiber Arrays

Abstract

A novel dye-sensitized solar cell (DSSC) architecture based on vertically aligned carbon nanofibers coated with a thin nanoneedle-textured anatase TiO2 film is demonstrated. An encouraging overall conversion efficiency of approximately 1.09% and a rather high open-circuit voltage of approximately 0.64 V have been achieved. The efficient charge separation at the TiO2-CNF junction and the large outer TiO2 surface of this core-shell architecture provide new methods to tune the materials and interfaces in solar cells.

Solar Energy Materials

“…The SEM images of templates prepared by Bwana are shown in Figure 3.36. [188] The templates are immersed in a TiO 2 precursor solution which contains titanium isopropoxide as a Ti source, and then removed and The V OC values were high for the nanorod systems, considered to be a result of the higher density of packed TiO 2 particles making up the structure and the reduced surface area exposed to the electrolyte where recombination with triiodide can take place, compared with the [189] with kind permission of Springer Science and Business Media nanoparticle and nanotube electrodes. The higher photocurrents for the organised structures were attributed to higher charge collection efficiencies because of the vectorial electron transport and reduced charge hopping (in random directions) across grain boundaries which is necessary for nanoparticle systems.…”

“…Alternatively, nanorods, wires or fibres can be grown by plasmaenhanced chemical vapour deposition using a nickel catalyst. [189] An electric field is applied during the deposition process which aligns the growth vertically from the substrate to give a free-standing, brushlike array of anatase nanowires with diameters 50-100 nm and length <40 mm (Figure 3.39). Chemical vapour deposition from titanium isopropoxide can then be used to grow 'nanoneedles', 10-15 nm in diameter, 50-100 nm in length, from the vertically aligned nanowire cores.…”

“…Reprinted from Bwana, 2008[189] with kind permission of Springer Science and Business Media 37 SEM images of (a) TiO 2 nanotubules and (b) nanorods synthesised in anodic alumina templates after removal of the templates. Reprinted fromBwana, 2008 …”

Performance of Dye‐Sensitized Solar Cells Based on MWCNT/TiO2–xNx Nanocomposite Electrodes

“…However, although the architecture is promising, it needs to be optimized since the energy conversion efficiency of such DSCs is only about 1.09 %. [16] Although many reports on CNTs/TiO 2 have been published, to the best of our knowledge, DSCs based on the photoelectrode of CNTs/TiO 2-x N x have not been reported so far. In our previous work, we have successfully introduced N-doped TiO 2 to the photoelectrodes of DSCs.…”

Anatase Titanium Dioxide Coated Single Wall Carbon Nanotubes Manufactured by Sonochemical-Hydrothermal Technique

“…Generally, most of these processes are either time consuming, cumbersome, expensive, lack the control for the deposition TiO 2 , and/or produce inferior results. A list of some of these processes include sol-gel [14][15][16][17][18], sol [19,20], hydrothermal [21,22], solvothermal [23], electrochemical oxidation [24], electrochemical deposition [25,26], electrophoretic co-deposition of TiO 2 -CNT films and deposition of TiO 2 onto CNT [27][28][29], alternative methods of sonochemical [30,31], chemical vapor deposition [32][33][34][35][36], and heterogeneous coagulation [37][38][39][40].…”