Design of Metal Free Fluorescent Pyridine Dyes Anchored on Cadmium Sulfide Nanowires: Optical, Electrochemical and Photovoltaic Applications.

Through a facile two-step synthetic procedure, three metal-free organic dyes having D-π-A kind of structure, belonging to chalcone family have been designed, produced and anchored on one dimensional cadmium sulfide nanowires (1D CdS NWs) to serve as a light energy harvester through dye-sensitized solar cells (DSSC) assembly. In order to anchor dye on CdS NWs nano-network, solution chemistry has been used in an easy and effective manner. The sensitizing capability of synthesized materials has been evaluated using optical and electrochemical studies, density functional theory (DFT) simulations, and photovoltaic performances. In line with a detailed analysis of fabricated Dye sensitized solar cells containing T4PC a photovoltaic efficiency yields 4.35 times (0.487%) more than that of bare CdS NWs (0.112%), while the other devices having T3PC and T2PC have shown 3.0 (0.338%) and 2.40 (0.273%) times greater photovoltaic efficiencies, respectively under standard light illumination. The obtained results offer solid evidence in favour of boosting external quantum efficiency (EQE) and reflect good agreement with the optical studies.

Core-shell cadmium sulphide @ silver sulphide nanowires surface architecture: Design towards photoelectrochemical solar cells.

Design and development of cadmium sulphide core with silver sulphide shell assembly in nanowire (NWs) surface architecture has been explored through room temperature, simple chemical route towards photoelectrochemical solar cell application. Incorporation of low band gap Ag2S nanoparticles over the outer surface of the chemical bath deposited CdS NWs has been achieved by simple cation exchange route based on negative free energy of formation. Shell optimization has been performed by investigating structure, surface morphologies and optical analyses and correlated with the photovoltaic parameters. Interestingly, core-shell CdS NWs/ Ag2S exhibits 1.5 better performance in terms of linear voltammetry, photocurrent transient response and the photo stability than bare CdS. Furthermore, three-fold enhancement in photoelectrochemical conversion efficiency have been observed for optimized FTO/ CdS NWs/Ag2S compared to bare FTO/CdS NWs due to the augmented light harvesting and condensed charge recombination. External quantum efficiency exhibits 24% for the optimized CdS NWs/ Ag2S core shell structure. Mott-Schottky and electrochemical impedance spectroscopy measurements have been used for better understanding the impact of gradual growth of Ag2S over CdS NWs which directly influences the overall photocurrent density of the devices.