Monolithic Quasi-Solid-State Dye Sensitized Solar Cells Prepared Entirely by Printing Processes

A complete printing process was developed to fabricate the quasi-solid-state dye-sensitized solar cells with monolithic structures (m-QS-DSSCs). First, a structure of m-DSSCs was constructed by sequentially printing TiO2 layers (main and scattering), a ZrO2 insulating layer, and a carbon counter electrode (CE) onto an FTO substrate (FTO/TiO2/ZrO2/carbon CE). Then, a quasi-solid-state printable electrolyte (QS-PE), prepared using polyethylene oxide/ polymethyl methacrylate, was printed directly on top of the porous carbon counter electrode (CE), enabling the m-QS-DSSCs to be prepared entirely by printing processes. In this study, the porous structures and characteristics of the ZrO2 and carbon layers were optimized by controlling the film thicknesses and heat treatment conditions; furthermore, the Pt layer was coated to improve the catalytic activity of carbon CEs. The results revealed that an appropriate porous structure of carbon and ZrO2 films could be obtained by heating the films from 200 to 500 degrees C. Through these porous layers, the QS-PE can penetrate well into the photoelectrodes, increasing the charge transport in the cells and at the electrode/electrolyte interfaces; therefore, the m-QS-DSSCs can achieve an efficiency of 6.79% under 1 sun illumination. Furthermore, the structures can also be utilized to fabricate liquid cells for application in a dim light environment. The m-QS-DSSCs remained stable during a long-term stability test at room temperature.

Automated summary

A complete printing process was developed for the fabrication of monolithic quasi-solid-state dye-sensitized solar cells (m-QS-DSSCs). The structures were constructed by printing TiO2 layers, a ZrO2 insulating layer, and a carbon counter electrode (CE) onto an FTO substrate, followed by printing a quasi-solid-state printable electrolyte (QS-PE) on top of the porous carbon CE. The optimized porous structures and characteristics of the ZrO2 and carbon layers enabled the m-QS-DSSCs to achieve an efficiency of 6.79% under 1 sun illumination.