Influence of Synthesis Temperature on Optical Characteristics of Polyaniline Doped with Dodecylbenzene Sulfonic Acid (PANI DBSA) for Advanced Optoelectronics Application

This study investigates the effects of synthesis temperature on the optical properties of polyaniline (PANI) doped with dodecyl benzene sulfonic acid (DBSA) over a range of temperatures (-5°C to 40°C). The PANI DBSA a conducting polymer with potential applications in optoelectronic devices and sensors was synthesized by self-dispersed emulsion polymerization. The optical properties of PANI DBSA thin films were characterized using UV-Vis spectroscopy in the wavelength range of 230nm-1099.77nm. Results show that the absorbance spectrum of PANI: DBSA thin films undergoes significant changes, with a redshift and intensity decrease at higher temperatures. Specifically, the absorbance peak wavelength shifts from 839.39 nm at -5°C to 792.31 nm at 40°C, accompanied by a reduction in intensity. The optical bandgap and optical conductivity of PANI-DBSA were found to decrease with increasing temperature, indicating enhanced electronic delocalization and density. The band gap was 1.37 eV, 1.20 eV, and 1.07 eV. Materials with band gap energies as low as 1.07 eV have applications in thermoelectric devices or solar cells.