Quasi-Solid-State Dye-Sensitized Solar Cells for Efficient and Stable Power Generation under Room Light Conditions

Highly efficient quasi-solid-state dye-sensitized solar cells (QS-DSSCs) are fabricated using nanocomposite gel electrolytes and applied under room light conditions (200 lx). To obtain high energy conversion efficiency in QS-DSSCs, the important components of the DSSC are systematically optimized based on their performance in liquid-state DSSCs. It shows that the liquid cell using the 3-methoxypropionitrile-based cobalt electrolyte has higher efficiency (18.91%) than the cell using the acetonitrile-based electrolyte (17.82%) under 200 lx illumination due to the higher charge recombination resistance at the photoelectrode/electrolyte interface for the 3-methoxypropionitrile system. Poly(vinylidene fluoride-co-hexafluoropropylene) is utilized as the gelator of the liquid electrolytes to prepare polymer gel electrolytes. Furthermore, to improve the performance of the QS-DSSCs, different metal oxide nanoparticles are introduced as nanofillers of the polymer gel electrolytes. It shows that the zinc oxide nanofillers have a superior performance in increasing the cell efficiency and the energy conversion efficiencies of the QS-DSSCs are higher than those of the corresponding liquid cells. By regulating the concentration of the zinc oxide nanofillers, the efficiency of the 3-methoxypropionitrile based QS-DSSC can achieve a value of 20.11% under 200 lx illumination. This QS-DSSC has a long-term stability at 35 degrees C.