Blueberry-shaped Fe2O3-FeOCl/poly-1H-pyrrole nanocomposite for ultraviolet and visible light sensing

Abstract

A highly efficient Fe₂O₃-FeOCl/poly-1H-pyrrole (Fe₂O₃-FeOCl/P1HP) nanocomposite thin-film optoelectronic device for photon sensing in both UV and visible light has been successfully fabricated in a one-step process. The synthesis involves the oxidation of 1H-pyrrole using (NH₄)₂S₂O₈ and Fe(NO₃)₃, forming a thin-film nanocomposite. With a bandgap of 2.35 eV and a distinctive blueberry-shaped morphology with particle sizes between 10 and 20 nm, this material demonstrates significant potential for light sensing applications. Its performance was assessed through electrical measurements, including current density under both illuminated (J_ph) and dark (J_o) conditions. The device produced J_ph values of 0.23, 0.22, 0.17, and 0.04 mA/cm² with Jo measured at 0.005 mA/cm² while exposed to photons with energies of 1.8, 2.3, 2.8, and 3.6 eV, i.e., 730, 540, 440, and 340 nm wavelengths, correspondingly. Responsivity (R) was observed to decrease from 2.3 mA/W at 340 nm to 1.8 mA/W at 540 nm, while detectivity (D) fell from 0.52 × 10⁹ Jones to 0.4 × 10⁹ Jones over the same wavelength range. At 730 nm, both R and D values dropped significantly to 0.4 mA/W and 0.1 × 10⁹ Jones, correspondingly. These positive results from the electrical tests highlight the efficiency of the light sensor across both the UV and visible spectra, making it ideal for industrial applications.