Investigation of 4-pyridyl liquid crystals on the photovoltaic performance and stability of dye sensitized solar cells by the co-sensitization

Abstract

Two dual functional molecules 3N and 3N-1 have been utilized to demonstrate the effects of the rod-like liquid crystals (LCs) on dye-sensitized solar cells (DSSCs). The newly developed compounds were characterized by traditional spectrum methods, and the LC properties were investigated through differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). DSSCs were assembled to evaluate the photovoltaic properties. The results show that both 3N and 3N-1 have broad nematic phase temperature intervals during the cooling cycle, and also gain photovoltaic properties on DSSCs as individual dyes. Meanwhile, these two LCs show different effects on the long-term stability and photo-conversion efficiency of the co-sensitized DSSC 3N/AZ6 or 3N-1/AZ6. The loading mode and the dye-desorption mechanism of dyes were also investigated by ATR-IR spectroscopy and DFT calculations.