Applied Surface Science, Vol.452, 337-351, 2018
Experimental and DFT insights into molecular structure and optical properties of new chalcones as promising photosensitizers towards solar cell applications
A new series of (hydroxyl-arylazo)-chalcone derivatives (5a -> e) has been prepared by condensation of 4-(4-acetylphenyl)-azo dyes 3 with 4-anisaldehyde in basic medium. The chemical structures were confirmed by elemental analysis, FT-IR, H-1 NMR and Mass Spectra. The thin films of chalcone derivatives have been prepared using thermal evaporation technique under vacuum pressure of 10(-5) mbar. The structural formation of these pristine films has been investigated using the field emission scanning electron microscopy (FESEM) and showed nanorod-structured chalcone thin films. The optical features of films are studied using spectrophotometric technique in the spectral wavelength range 200-2500 nm, from which the optical constants and the dispersion parameters are calculated. To identify these obtained experimental results, DFT calculations have been carried out at the B3LYP/6-311G (d, p) level of theory. The value of transport energy (E-t) computed from DFT can exceed the value of optical energy gap (E-g(opt)) determined from UV-vis spectroscopy by 0.45-1.15 eV due to the exciton binding energy (E-B). Unraveling the correlated structural and optical properties of chalcones 5a -> e with photosensitizertype structure open up the avenue towards fabrication organic/inorganic hybrid (chalcone 5e/silicon) heterojunction solar cell. The optoelectronic properties and photovoltaic parameters of the cell have been studied. (C) 2018 Elsevier B.V. All rights reserved.