Dielectric and optical properties of YVO₄/MgO/CNT/Hb-modified polyurethane composites prepared via laser ablation for electrical and optical applications

Investigations are conducted on the possibilities of thermoplastic polyurethane (TPU)-based composite films for optoelectronic applications. The tested films were examined using scanning electron microscopy, X-ray diffraction spectroscopy (XRD), and Fourier transform infrared spectroscopy (FTIR). This paper investigated the AC conductivity, dielectric constant, and optical band gap. The MgO particle size decreased from 3.4 to 0.6 µm with carbon nanotube (CNT) addition. Across the frequency range of 0.1 Hz to 20 MHz, the dielectric constant decreased, while AC conductivity increased. Notably, at low frequencies (0.1 Hz), the CNT-containing composite exhibited a significant permittivity (ε′) of ~ 84,500, compared to a maximum of 1100 for other composites. The direct band gap of pure TPU is 3.4 eV, while composites ranged from 2.0 to 2.8 eV. Y(VO₄)/MgO/CNT/Hb@TPU showed thermal stability up to 300 °C. The resulting films demonstrate potential in optoelectronic applications.