Aging effect in dye-sensitized solar cells sealed with thermoplastic films

Abstract

Purpose The purpose of this paper is to elucidate the aging effect in dye-sensitized solar cells (DSSCs) sealed with thermoplastic film and to compare it with unsealed DSSCs. Design/methodology/approach The paper presents the steps of the fabrication of standard DSSC, as well as the DSSC-sealing processes, by using thermoplastic film. Current-voltage characterization was performed to observe the changes in efficiency, fill factor, short circuit current density and open circuit voltage for both unsealed and sealed DSSCs for aging time up to 336 h. Findings The unsealed DSSC showed significant drop in efficiency from 4.26 to 2.42 per cent within the first 5.5 h of aging time because of the leakage and volatilization of the solvent in the electrolyte. On the other hand, the sealed DSSC exhibited a gradual improvement of efficiency from 4.16 to 4.73 per cent after the first 216 h of aging time. The initial efficiency increment can be ascribed to the improved adsorption of electrolyte into the titanium dioxide film because of the gradual desorption of excess dye from TiO2 with increasing aging time. Originality/value This paper demonstrates the importance of the proper sealing process for the long-term operation of DSSC.