Experimental investigation of spin coating acceleration effect on the DSSC performance

Abstract

Abstract The optimization of the TiO2 mesoporous structure plays significant role in dye-sensitized solar cell (DSSC) to produce efficient devices. In this study, the TiO2 mesoporous layer was coated by using a spin coating equipment with different spin accelerations. As a consequence of this investigation, the impacts of the spin coating acceleration on the optoelectronic and electrical performance characteristics of the DSSC were investigated. It has been shown that altering the spin coating acceleration has a direct impact on the mesoporous layer, which in turn influences the absorption ability of dye. The light absorbance of the sample A5 (coated at 2000 rpm s−1) ascended drastically in accordance to other samples. Thanks to this augmentation in absorbance, the current density (J SC ) and power conversion efficiency (PCE) values also improved. According to electrochemical impedance spectroscopy analysis, it was attained that recombination resistance values increases with the rising spin coating acceleration rates after 500 rpm s−1 and reaches up to highest value at 2000 rpm s−1. A relatively longer electron lifetime of 40.36 ms and recombination resistance of 12.22 Ω were obtained for the device coated at the rate of 2000 rpm s−1. The device coated at a rate of 2000 rpm s−1 had a PCE (5.51%) that was superior than other devices because of its improved light collecting ability, quick electron transport, suppressed electron recombination, and having longer electron life time. As a starting point for future investigations and applications, results of present study provide an insight into the optimal spin coating parameters for DSSC applications.