Experimental and theoretical study on the optical and morphological properties of highly photoluminescent material 2,4,5-triphenyl imidazole

The 2,4,5-Triphenyl Imidazole (TPI) C₂₁H₁₆N₂ samples were deposited as thin film by means of the physical vapor deposition (PVD) on glass and silicon substrates. As well as, three solutions with different concentrations using dimethyl sulfoxide (DMSO) solvent. The physical properties of all samples were investigated using different techniques. The thin film’s morphology was examined using atomic force microscopy (AFM) of the sample on silicon substrates, revealing a highly rough surface. The optical characteristics of both the thin film on glass substrate, the solutions, and the powder were studied through transmittance and absorbance measurements, which helped determine a value of the band gap of 3.45 eV. Photoluminescence and thermal photoluminescence spectroscopy showed the high emission of the material in its different aspects. Theoretical simulations of the HOMO–LUMO gap and electronic absorption spectra were obtained using the density functional theory (DFT) approach.