Dependence of solar cell performance on the nature of alkaline counterion in gel polymer electrolytes containing binary iodides

• Published in: Journal of solid state electrochemistry Vol. 21; no. 6; pp. 1571 - 1578
• Main Authors: Bandara, T. M. W. J., Fernando, H. D. N. S., Furlani, M., Albinsson, I., Dissanayake, M. A. K. L., Ratnasekera, J. L., Mellander, B.-E.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 2017; Springer Nature B.V
• Subjects: Alkaline cation; Analytical Chemistry; cation; Cations; Cesium; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Circuits; Condensed Matter Physics; Conductivity; Dye-sensitized; Dye-sensitized solar cells; Dyes; Efficiency; efficiency enhancement; Electrochemistry; Electrolytes; Electrolytic cells; Energy conversion efficiency; Energy Storage; Fysik; Iodides; Ion currents; ionic-conductivity; Lithium; lithium batteries; Molten salt electrolytes; Open circuit voltage; Original Paper; Photo-electrochemical; Photovoltaic cells; Physical Chemistry; Physical Sciences; Polyacrylonitrile; Polymer electrolyte; Polymers; Quasi-solid state; Room temperature; Rubidium; salts; Short circuit currents; size; Sodium; Solar cell; Solid electrolytes; Solid state; Thermal conductivity; Thin films; Titanium dioxide; Solar cell; Photo-electrochemical; Polymer electrolyte; Dye-sensitized; Quasi-solid state; Alkaline cation
• ISSN: 1432-8488; 1433-0768; 1433-0768
• DOI: 10.1007/s10008-017-3518-2

Performance of dye-sensitized nano-crystalline TiO 2 thin film-based photo-electrochemical solar cells (PECSCs) containing gel polymer electrolytes is largely governed by the nature of the cation in the electrolyte. Dependence of the photovoltaic performance in these quasi-solid state PECSCs on the alkaline cation size has already been investigated for single cation iodide salt-based electrolytes. The present study reports the ionic conductivity dependence on the nature of alkaline cations (counterion) in a gel polymer electrolyte based on binary iodides. Polyacrylonitrile-based gel polymer electrolyte series containing binary iodide salts is prepared using one of the alkaline iodides (LiI, NaI, KI, RbI, and CsI) and tetrapropylammonium iodide (Pr 4 NI). All the electrolytes based on binary salts have shown conductivity enhancement compared to their single cation counterparts. When combined with Pr 4 NI, each of the Li + , Na + , K + , Rb + , and Cs + cation containing iodide salts incorporated in the gel electrolytes has shown a room temperature conductivity enhancement of 85.59, 12.03, 12.71, 20.77, and 15.36%, respectively. The conductivities of gel electrolytes containing binary iodide systems with Pr 4 NI and KI/RbI/CsI are higher and have shown values of 3.28, 3.43, and 3.23 mS cm −1 , respectively at room temperature. The influence of the nature of counterions on the performance of quasi-solid state dye-sensitized solar cells is investigated by assembling two series of cells. All the binary cationic solar cells have shown more or less enhancements of open circuit voltage, short circuit current density, fill factor, and efficiency compared to their single cation counterparts. This work highlights the importance of employing binary cations (a large and a small) in electrolytes intended for quasi-solid state solar cells. The percentage of energy conversion efficiency enhancement shown for the PECSCs made with electrolytes containing Pr 4 NI along with Li + , Na + , K + , Rb + , and Cs + iodides is 260.27, 133.65, 65.27, 25.32, and 8.36%, respectively. The highest efficiency of 4.93% is shown by the solar cell containing KI and Pr 4 NI. However, the highest enhancements of ionic conductivity as well as the energy conversion efficiency were exhibited by the PECSC made with Li + -containing binary cationic electrolyte.