Investigation of the structural and optoelectronic properties and nonlinear characteristics of poly(O-toluidine)/inorganic materials

The present manuscript explored the synthesis and comprehensive characterization of pure Poly(O-toluidine) (POT) and K-, KI-, and Mg-doped POT films. They were synthesised on micro-glass substrates using a straightforward chemical process. Morphological, optical properties, as well as the electrical characteristics of POT and POT doped with different inorganic materials were studied. The average thickness of the prepared films was arranged to be approximately equal to 2 mu m for K-, KI-, and Mg-doped POT films. The polymer films prepared were analysed by the use of FT-IR. To identify the nature, and structure of the surfaces of the prepared films and to measure the particle size of the grain Atomic Force Microscopy (AFM) was used. The produced films' optical characteristics were examined, and the absorption spectroscopy for wavelengths between 300 and 800 nm was recorded. In addition to the refraction index, n(refx), and the extinction coefficient, kex, measurements were taken of the absorption coefficient and the prohibited energy gap to transmission directly. The estimated energy gaps of pure POT is 3.1 eV, while the obtained values of energy gaps were 3.25, 2.65, and 3.15 eV for K-POT, KI-POT, and Mg-POT, respectively. The electric conductivity was also studied and it was found that the films correlate with the ohmic behavior at the measured volts range. The I-V curves have shown slight elevation with raising the temperature from 303 to 373 K. The thermal nonlinear refractive indices of the POT films are determined using open and closed Z-scan technique. The experimental results proved that the sample K-, KI-, and Mg-doped POT films showed a high nonlinear refraction index in the range of 10(-7) calculated by the Z-scan method under low input power of 18 mW, which indicates that the K-, KI-, and Mg-doped POT film is a good candidate to be used in all optical device applications especially for optical limiter capabilities.