A study on fabrication and characterization of dye sensitized solar cells with carissa spinuram, iresine herbstii and ipomoea purpurea as sensitizers in visible light

In this work, dye extracts of carrisa spinuram, iresine herbstii and ipomoea purpurea (morning glory), were used as natural dyes in titanium (II) oxide (TiO 2 ) nanoparticles-based dye sensitized solar cells (DSSCs). Fourier Transform Infrared (FTIR), Ultraviolet-Visible (UV-Vis), Photoluminescence (PL), and electrochemical impedance spectroscopy were utilized to study the functional groups, optical response, and redox-oxidation potentials of these extracted dyes respectively. The energy bands like highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of these dyes were determined by employing cyclic-voltammetry (CV) and as well as optical absorption techniques. The FTIR data of under study dyes show various function groups. The associated groups corresponding to electron transferring entity are also observed in them. These dyes were excited with 530 nm wavelength and in reverse they emitted in yellow and red regions of the electromagnetic spectrum. Based on these emitted photons, they can potentially be used as chromophores and can lead a good efficiency in the DSCCs. The different photovoltaic parameters of these dyes (as photosensitizer) in the prepared DSSCs were estimated from current–voltage (I-V) data. The life time of minority carriers and the external quantum efficiency (EQE) were obtained from open circuit voltage decay (OCVD) method and incident photon to current efficiency (IPCE) technique respectively. The carrisa spinuram dye based solar cell (SC) showed highest photovoltaic response of around 424mV open circuit voltage (V OC ) and 5.2mA/cm 2 short circuit current density (J SC ) with an SC efficiency (ɳ%) of 1.1952% and efficiency in ipomoea purporea and iresine herbstii dye-based cells was recorded around 0.87927% and 0.55976% respectively. The same photovoltaic parameters in red, green, blue light were also investigated. The present work demonstrates the potential of these dyes in TiO 2 based DSSCs.