Studying the effect of annealing temperature on the optical characteristics of conjugated pyrrolo[2,3-b]pyrrole azo dye thin films for optoelectronic devices

Abstract

Thin films of pyrrolo[2,3- b ]pyrrole derivative newly synthesized and characterized by FT-IR, NMR spectroscopies , and elemental analysis has been prepared by thermal evaporation technique. The optical absorbance, transmittance , and reflectance measurements were carried out in the wavelength (300–2500 nm) range. The allied absorption, dielectric and dispersion parameters which are significantly influenced by RT – thermal agitation, and annealing have been depicted, investigated, discussed and compared with other reported results. The electronic transition energies (2.43& 3.20 eV) were deduced and correlated to the optical, and energy gaps, respectively. The thin films' high absorption coefficient values and other optical metrics demonstrated their promise for use in light emitting and solar absorbing applications. • Synthesize a new organic compound namely pyrrolo[2,3- b ]pyrrole and investigated by FTIR, HNMR, and elemental analysis. • Thin film forms have been prepared by thermal evaporation technique. • Identification and discussion of the electronic transition energies through HOMO – LUMO orbitals. • Studying the RT-thermal agitation, and annealing effects on the number, intensity and the energy positions of the excitonic absorption peaks. • Thin films have proved their promises to be applied in solar cells, light emitting.