High-Performance UV-Vis-NIR Photodetectors Based on PEDOT Obtained by Plasma-Enhanced Chemical Vapor Deposition

This study presents the fabrication of organic UV-vis-NIR photodetectors based on poly(3,4-ethylenedioxythiophene) (PEDOT) thin films synthesized via a plasma-enhanced chemical vapor deposition at 10, 20, and 30 W plasma power. The effects of plasma power on polymerization, as well as optical, structural, morphological, and optoelectronic properties, are analyzed using UV-vis, Fourier transform infrared spectroscopy, scanning electron microscope, and scanning electron microscopy-energy-dispersive X-ray. The films, exhibiting a bandgap of 3.52-3.59 eV, are uniformly coated on Si surfaces. Photodiode and photodetector performance is evaluated through current-voltage and current-transient measurements under varying light intensities and wavelengths. PEDOT films synthesized at 10 W exhibit superior photodetector performance, with maximum responsivity and detectivity of 0.0975 A W-1 and 1.65 & times; 10(1)(0) cm Hz(0.5) W-1 at 900 nm, and a noise-equivalent power of 5.38 & times; 10(-)(1)(2) W Hz(-)(1)(/)(2). Maximum external quantum efficiency is recorded as 23.975% at 450 nm. These results emphasize the suitability of low-power PEDOT films for optoelectronic applications due to their superior morphology and optoelectronic characteristics.