Synthesis, physicochemical and spectroscopic characterizations of azochalcone derivative thin films towards solar cells application

Abstract

A novel azochalcone derivative (ACh) has been synthesized by the reaction of azo-ketone and 4-anisaldehyde in ethanolic NaOH. The synthetized compound was characterized by FT-IR, 1H NMR, and Mass spectra. Thin films with various thickness of ACh were deposited by thermal evaporation technique onto glass, quartz and Si wafer substrates under vacuum of 10−5 Torr. Structural analysis of these thin films was investigated by the field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) patterns. The optical constants such as: refractive index (n), extinction coefficient (k) and optical band gap (Eg) of pristine and annealed films have been studied in the wavelength region 200–2500 nm. Analysis of the absorption coefficient, α, spectrum shows that the most probable transition is the indirect allowed transition. The onset and fundamental optical band gaps for ACh film are found to be 2.44 and 3.37 eV, respectively. The annealing temperature changes the optical constants. Tunable structural and optical properties of ACh open up the avenue to building up the solar cell based on ACh. The electronic transport mechanisms and photovoltaic properties of the fabricated solar cell of Au/ACh/p-Si/Al have been studied.