A Thermoplastic Gel Electrolyte for Stable Quasi‐Solid‐State Dye‐Sensitized Solar Cells

Abstract

Dye‐sensitized solar cells (DSSCs) are receiving considerable attention as low‐cost alternatives to conventional solar cells. In DSSCs based on liquid electrolytes, a photoelectric efficiency of 11 % has been achieved, but potential problems in sealing the cells and the low long‐term stability of these systems have impeded their practical use. Here, we present a thermoplastic gel electrolyte (TPGE) as an alternative to the liquid electrolytes used in DSSCs. The TPGE exhibits a thermoplastic character, high conductivity, long‐term stability, and can be prepared by a simple and convenient protocol. The viscosity, conductivity, and phase state of the TPGE can be controlled by tuning the composition. Using 40 wt % poly(ethylene glycol) (PEG) as the polymeric host, 60 wt % propylene carbonate (PC) as the solvent, and 0.65 M KI and 0.065 M I2 as the ionic conductors, a TPGE with a conductivity of 2.61 mS cm–2 is prepared. Based on this TPGE, a DSSC is fabricated with an overall light‐to‐electrical‐energy conversion efficiency of 7.22 % under 100 mW cm–2 irradiation. The present findings should accelerate the widespread use of DSSCs.

Key technological elements in dye-sensitized solar cells (DSC)

“…Solid-state and quasi-solid-state electrolytes such as polymer gel electrolytes [88][89][90][91][92][93][94], organic and inorganic hole transporting materials [95][96][97][98][99][100][101], ionic liquids [102][103][104][105][106], and polymer electrolytes [107][108][109][110][111][112] have been suggested in order to replace the conventional liquid electrolyte. Polymer gel electrolytes (PGEs) could reduce the leakage by retaining solvent molecules in the polymer matrices.…”

Scattering-layer-induced energy storage function in polymer-based quasi-solid-state dye-sensitized solar cells

“…Polymer-based DSSCs are one kind of popular quasi-solid-state DSSCs owing to their excellent characteristics such as easy fabrication, low cost, good stability, and flexibility. [14][15][16][17][18][19][20] Although scattering layer is not usually applied in such cells due to the reduction of electron transport, our findings show that adding a scattering layer of large TiO 2 nanoparticles in a polymer-based quasi-solid-state DSSCs could form scattering layer/polymer matrix structure for energy storage. There was no additional structure for energy storage on the CE of such PSC.…”

The optimisation of dye sensitised solar cell working electrodes for graphene and SWCNTs containing quasi-solid state electrolytes

“…high temperature instability and additional complexity in trying to contain liquids in a solar cell device during manufacturing (Lee et al, 2010a;Wang et al, 2003c;Wu et al, 2007b).…”