Performance of polymer electrolyte based on chitosan blended with poly(ethylene oxide) for plasmonic dye-sensitized solar cell

• Conductivity increased in the polymer electrolyte blend system.
• More NH4I can be accommodated in chitosan-PEO host compared to chitosan-PVA host.
• Electrolyte is mainly ionic conductor as proven by transference number measurement.
• Efficiency of DSSC increased 44.9% with addition of Ag nanoparticles.

Chitosan and poly(ethylene oxide) powders have been mixed in different weight ratios. To each mixture, a fixed amount of ammonium iodide has been added. All mixtures have been dissolved in 1% acetic acid solution to form polymer blend electrolyte films by the solution cast technique. X-ray diffraction indicates that the polymer blend electrolytes are amorphous. Fourier transform infrared spectroscopy shows shifting of the amine, carboxamide and COC bands to lower wavenumbers indicating the occurrence of complexation. Electrochemical impedance spectroscopy has been used to study the electrical properties of the samples. The ionic conductivity for 55 wt.% chitosan–45 wt.% NH4I electrolyte system is 3.73 × 10−7 S cm−1 at room temperature and is increased to 3.66 × 10−6 S cm−1 for the blended film (16.5 wt.% chitosan-38.5 wt.% PEO)–45 wt.% NH4I film. Dye-sensitized solar cells (DSSCs) have been fabricated by sandwiching the polymer electrolyte between the TiO2/dye photoelectrode and Pt counter electrode. DSSCs fabricated exhibits short-circuit current density (Jsc) of 2.71 mA cm−2, open circuit voltage (Voc) of 0.58 V and efficiency of 0.78% with configuration ITO/TiO2/N3 dye/(16.5 wt.% chitosan-38.5 wt.% PEO)–45 wt.% NH4I(+I2)/Pt/ITO and Jsc of 2.84 mA cm−2, Voc of 0.58 V and efficiency of 1.13% with configuration ITO/TiO2 + Ag nanoparticles/N3 dye/(16.5 wt.% chitosan–38.5 wt.% PEO)–45 wt.% NH4I(+I2)/Pt/ITO.