Photovoltaic performances of dye-sensitized solar cells assembled with chemically cross-linked gel polymer electrolytes

Abstract

In Part Ⅰ , Quasi-solid-state dye-sensitized solar cells (DSSCs) were assembled by in-situ chemical cross-linking of a gel electrolyte precursor containing liquid electrolyte. The DSSCs assembled with this cross-linked gel polymer electrolyte showed higher open circuit voltage and lower short-circuit photocurrent density than those of DSSCs with liquid electrolyte. Addition of SiO2 nanoparticles into the cross-linked gel polymer electrolyte significantly improved the photovoltaic performance and long-term stability of the DSSCs. The optimized quasi-solid-state DSSC showed high conversion efficiency, 6.2 % at 100 mWcm− 2 with good durability. In Part Ⅱ , Cross-linked gel polymer electrolytes containing aluminum oxide nanoparticles were prepared by in situ chemical cross-linking after injection of the gel precursor into the dye-sensitized solar cell (DSSC). This made it possible to directly solidify the electrolyte in the cell and maintain good interfacial contacts between the electrolyte and the electrodes without suffering loss of performance in the DSSC. These gel polymer electrolytes exhibited high ionic conductivity and favorable charge transfer reaction at the interfaces of electrodes and electrolyte. The quasi-solid-state DSSC assembled with optimized gel polymer electrolyte exhibited remarkably high conversion efficiency, 6.34 % at 100 mWcm− 2, and better long-term stability, as compared to the DSSC with liquid electrolyte. In Part Ⅲ , A gel polymer electrolyte was prepared by in situ chemical cross-linking at room temperature without any initiators. The conversion efficiency of DSSCs with cross-linked gel polymer electrolyte decreased with cross-linking density. We investigated the electrochemical properties of gel polymer electrolytes cross-linked at room temperature, and their photoelectrochemical performance was evaluated. The quasi-solid- state DSSC assembled with the gel polymer electrolyte containing 20 wt.% Al2O3 nanoparticles exhibited a short-circuit photocurrent density of 10.97 mAcm-2, an open circuit voltage of 0.78 V and an overall conversion efficiency of 4.88 % under 100 mWcm− 2.