As the demand for flexible and wearable electronic devices with stand-alone power sources is increasing, the development of flexible and lightweight photovoltaic devices that can be integrated directly into products of complex shapes is becoming a major direction of photovoltaic applications.
The flexible dye solar cells (F-DSCs) usually consist of a photo anode coated with a dye-sensitized semiconductor layer on a flexible transparent conductive substrate, a counter electrode with a thin catalyst layer on a conductive substrate, and an electrolyte commonly containing iodine-based redox couple (I-/I3-).
Usually, transparent conductive plastic films (tin oxide indium/polyethylene naphthalate-ITO/PEN) or flexible metallic materials (titanium foils, titanium wires, titanium or stainless steel mesh, etc.) are used as flexible substrates.
Photo anodes using transparent conductive plastic film substrates cannot undergo high temperature (higher than 450℃) annealing to remove organic residues from the nanostructured film, and cannot form chemical bonds between the conductive layer and the semiconductor film, thus causing low charge transport and collection. Flexible photo anodes based on metal foil substrates can improve charge transport and collection by applying high temperature annealing treatment.
The metal film substrate is mostly titanium films or wires, and their high cost limits their wide application.
Therefore, it is necessary to develop new fabrication techniques based on low-cost substrates such as normal glasses, plastic and paper in order to replace the above substrates.
Jon Sang Mo, a researcher at the Faculty of Chemical Engineering, has proposed a novel structure of F-DSCs using TiO2 Nano paper as a flexible substrate and porous Ti BCE composed of metallic titanium particles as a collector electrode.
The PCE of F-DSCs with TiO2 Nano paper substrate and porous Ti BCE reach 4.38% under AM1.5G and 100mW·cm-2 simulated solar irradiation.
You can find more information in his paper “Flexible dye solar cells with TiO2 nanopaper and Ti back contact electrodes” in “Journal of Saudi Chemical Society” (SCI).
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