Low-temperature Preparation And Properties Of TiO₂ Electrodes For Flexible DSSC

Flexible dye-sensitized solar cells (DSSC) using transparent conductive plastic substrates have attracted a number of interests recently because they can reduce both the weight and the cost of the device. Plastic substrates can not endure high temperature. Therefore, it is significant to prepare TiO₂ thin film electrodes on the plastic at low temperature.Flexible TiO₂ thin film electrodes were prepared respectively by hydrothermal annealing and UV treatment after low-temperature sintering. In order to improve the photoelectric performance of flexible film electrode, the composite electrodes of P25 and TiO₂ nanotubes were fabricated by hydrothermal process. TiO₂ nanotubes were characterized by means of TEM, XRD and nitrogen adsorption–desorption isotherms. And the TiO₂ thin film electrodes were characterized individually by fourier transform infrared spectroscope (FTIR), ultraviolet visible spectrometer (UVSP) and field emission scanning electron microscope (FESEM). Moreover, the photoelectric performances of the flexible DSSC were measured in this work.It is found that the TiO₂ thin films prepared by two methods above are porous. The TiO₂ thin film electrode prepared by UV treatment after low-temperature sintering possesses the short circuit current of 4.9mA and the solar-to-electric energy conversion efficiency of 1.28%. And the TiO₂ thin film electrode fabricated by hydrothermal annealing for flexible DSSC has 1.32% of solar-to-electric energy conversion efficiency with a stable performance and the short circuit current of 2.6mA.The diameter, length and specific surface area of titania nanotubes prepared by 150℃48h is 10nm, 0.5¹Î¼m and 405.8cm2/g respectively. The photoelectric performance of the film electrodes consisted of titania nanotubes prepared by 150℃48h is best. 400℃sintering temperature of titania nanotubes is best for the photoelectric performance of TiO₂ electrode. When the content of titania nanotubes is 5%, the film electrodes for flexible DSSC can achieve the best photoelectric performance with the short circuit current of 3.25mA and the solar-to-electric energy conversion efficiency of 1.67%.