For developing marketable flexible solar cells, it is necessary to develop flexible transparent electrodes with properties that are not affected by repeated bending. As such, for developing commercially viable high-efficiency flexible DSSCs, there is a need to develop effective heat treatment techniques that can be applied to flexible substrates, as well as flexible transparent electrodes that are affordable, durable, and corrosion-resistant.
In this research, SWCNT thin films used in photo-electrodes and counter-electrodes of DSSCs were prepared by depositing water-dispersed SWCNTs over a glass or flexible plastic substrates by using a spray method.
First of all, we combined spray-coating of aqueous dispersion solution of SWCNTs with chemical reduction of Pt precursor to fabricate fully solution-processed CEs. Because the solution processing was conducted entirely at low temperatures (< 150 C) our new CE-fabrication method that utilizes formic acid as a reduction agent is compatible with common electronics-grade plastic substrates, thereby lending potential for large-scale production at low cost
In addition, in this study developed a simple and effective rapid heat treatment process for TiO2 photo-electrodes by using a 2.45 GHz variable-output microwave oven built by modifying a commercial off-the-shelf product and simple holder. We successfully fabricated DSSCs less than 8 min using rapid heating method, comparable to conventional annealing process. This new strategy was also attempted in order to prepare SWCNT thin film transparent electrode of PEs, using TiO2 blocking layer made by combining with TiO2 sol solution and micro-wave sintering in Anisole solution.
