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

Abstract

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 × 1010 cm Hz0.5 W−1 at 900 nm, and a noise-equivalent power of 5.38 × 10−12 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.