Ultrafast Fabrication of Flexible Dye-Sensitized Solar Cells by Ultrasonic Spray-Coating Technology

Abstract

Dye-sensitized solar cells (DSSCs) are one of the most promising technologies for the renewable energy sources. From now, most research has been focused on how to increase the efficiency of the devices, while there has been no development of the rapid fabrication for the roll-to-roll process. Flexible DSSCs have a potential to introducing the roll-to-roll process Unfortunately, There are intrinsic barriers with dye adsorption and TiO2 sintering processes. In conventional process the dye molecules are adsorbed on the TiO2 surfaces by soaking which need to over 12h for penetrating into the TiO2 layer. Also, It is makes hard to control the amount of dye molecules adsorbed on the TiO2, which decrease the reproducibility. The TiO2 sintering process for interconnection between TiO2 nanoparticles need 500 ℃ high temperature on which Flexible electrode lose their properties. In this research, we have investigated novel, commercially viable deposition techniques for the preparation of TiO2 electrodes for flexible dye-sensitized solar cells by using a ultrasonic spray coating technology. These proposed new methods, namely pre-dye-coating and codeposition ultrasonic spraying, efficiently replace the conventional need for time-consuming processes such as dye soaking and high-temperature sintering, also, successfully replaced with a cold isostatic pressing (CIP) method. Power conversion efficiencies of over 4.0% were achieved with electrodes prepared on flexible polymer substrates using this new deposition technology and N719 dye as a sensitizer. These proposed new technologies are therefore believed to represent a new breakthrough in the fabrication of flexible DSC devices, and could be readily adapted to the mass production of large-area devices in the near future