Efficient dye-sensitized solar cells (DSSCs) through atmospheric pressure plasma treatment of photoanode surface
Haruna P. Wante, Joseph Aidan, Sabastine C. Ezike
Abstract
Atmospheric pressure plasma (APP) source was used for surface activation of polyetherimide (PEI) polymer substrate for dye-sensitized solar cells (DSSCs) fabrication. Changes in the water contact angle (WCA) and FE-SEM analysis of PEI samples before and after plasma treatment were used to assess the level of polymer surface activation. The changes improved the power conversion efficiency (PCE) of DSSC on PEI substrate. Radio frequency (RF) magnetron sputtering was used to deposit indium tin oxide (ITO) on the substrate at a thickness of 100 nm.TiO2-P25 powder was used in the preparation of the photoanode paste without the use of organic binder and doctor blade method was used for the deposition of the TiO2 paste. A reasonable increment in the PCE of about ca.60% from the plasma treated substrate was achieved when compared with the untreated substrate. This suggests that DBD plasma modification of flexible substrates has a significant favorable impact on DSSC efficiency. The charge transfer property of the cells was determined using electrochemical impedance spectroscopy (EIS). The Nyquist plot of EIS for treated substrate-based DSSC showed lower charge transfer resistance than the untreated substrate-based DSSC due to improved interconnecting path for electron transport.