Highly efficient donor–acceptor hydrazone dyes-inorganic Si/TiO2 hybrid solar cells

•D-bridge-A hydrazone dyes were synthesized and characterized by UV–Vis, FTIR, and NMR techniques.•The effect of different solvents has been studied on the absorption wavelengths.•Computed absorption and IR spectra are in good agreement with the experimental data.•Direct correlation between IPa/EAa and Voc has been observed.•Hetero-junction solar cell devices were fabricated and 3.12% efficiency has been observed for HD1.

We have synthesized the two donor-bridge-acceptor organic dyes (hydrazone dye 1 (HD1) and hydrazone dye 2 (HD2)) with the aim to enhance intra-molecular charge transfer then characterized by FTIR and NMR. The ground state geometries have been optimized at three different levels of theories, i.e., B3LYP/6-31G∗, B3LYP/6-31G∗∗ and Hartee–Fock HF/6-31G∗∗. The absorption spectra and oscillator strengths in different solvents have been computed and compared with the experimental data. The vibrational spectral assignments have been performed on the recorded FTIR spectra based on the theoretical predicted wavenumbers at three different levels of theories. The effect of different solvents (CHCl3, CH3CN and C2H5OH) has been studied on the absorption wavelengths. Furthermore, we have computed the ionization potentials, electron affinities and reorganization energies of studied compounds and shed light on the charge transport properties. The hetero-junction solar cell devices were fabricated by organic–inorganic hetero-junction (Si/TiO2/dye) then the efficiency has been measured by applying the incident power 30, 50 and 70 mW/cm2. The maximum efficiency 3.12% has been observed for HD1.

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