Efficient photosensitive light harvesting dye sensitized solar cell using hibiscus and rhodamine dyes

Co-sensitization is a powerful technique for achieving photosensitive light harvesting and enhancing dye sensitized solar cell (DSSC) performance. In this article, potential of extracted natural dye from Hibiscus sabdariffa and synthetic organic dye from Rhodamine as single dye source and mixed dyes are used to examine the performance of cells. The UV-Vis absorption spectra showed that examined dye mixture has cumulative absorption properties, such that its absorption spectra overlapped the spectral area. Moreover, DSSCs are characterized using UV-Vis Spectroscopy and Scanning electron microscopy (SEM). FTIR study was used to observe the functional groups of dye molecules to ensure the anchoring ability of dye to adsorb onto TiO2 layer. X-Ray diffraction spectrum analysis (XRD), Photovoltaic performance of cells, Energy dispersive spectroscopy (EDS), and Electrochemical impedance spectroscopy (EIS) were also conducted on the cells. The impedance spectra of dyes show minimum impedance of 17.5 Omega in case of mixed dye. XRD analysis recognizes small crystalline size that reveals anatase crystal phase of TiO2. Co-sensitized dye solar cell shows highest current density (Jsc) of 4.02mA and power conversion efficiency of 1.23%. The outcomes can be attributed to the light harvesting, the good optical condition, and the appropriate energy levels of the co-sensitized dye. Moreover, the homogenous dispersion causes effective dye loading on the surface of semiconductor.