Experimental and theoretical investigation of dye sensitized solar cells integrated with crosslinked poly(vinylpyrrolidone) polymer electrolyte using initiated chemical vapor deposition

By Smolin, Yuriy Y.; Janakiraman, Sruthi; Soroush, Masoud; Lau, Kenneth K. S.
Published in Thin Solid Films NULL 2016

Abstract

Abstract Initiated chemical vapor deposition is used to integrate crosslinked poly(vinylpyrrolidone) (PVP) as a polymer electrolyte into the mesoporous TiO2 photoanode of dye sensitized solar cells (DSSCs). By adjusting the fractional saturation ratio of ethylene glycol diacrylate (EGDA) crosslinker to vinylpyrrolidone (VP) monomer, the amount of crosslinker within the crosslinked polymer is controlled directly, and a minimum ratio of 0.2:1 (EGDA to VP) is found to form a robust insoluble crosslinked film. Fineman-Ross copolymer analysis indicates that both {VP} and {EGDA} prefer to polymerize with {VP} rather than with EGDA, likely due to reduced steric hindrance. {DSSCs} incorporating crosslinked {PVP} polymer electrolyte are found to have 51% higher power conversion efficiency (37% higher in open circuit voltage and 25% higher in fill factor) compared to {DSSCs} with liquid electrolytes. First-principles macroscopic mathematical modeling reveals that the polymer electrolyte shifts the conduction band of TiO2 (vs. normal hydrogen electrode) negatively, increases shunt resistance, and affects interfacial processes like back-electron surface recombination in the cell.

Read » Back