A feasibility method of constructing bilayer device for enhanced regulation in the mid-to-far IR region

Abstract

A dual-layer structure combining the properties of two polymers is demonstrated to be efficient in strengthening the mid-to-far infrared modulation. Prior to the assembly of bilayer devices, the infrared adjustment capability of single-layer devices poly(3,4-ethylenedioxythiophene) (PEDOT)、poly(pyrrole) (PPY) and poly(aniline) (PANI) with different polymerization charges is scrutinized. The results exhibit that the optimal polymerization charge affording the highest reflectance variation is inconsistent between the mid-wavelength and long-wavelength bands in PEDOT and PPY devices. However, through the arrangement of deposition sequence and relative thickness of PEDOT and PPY coatings, a device with the reflectance contrast of 0.662 in the mid-wavelength and 0.281 in the long-wavelength bands was obtained utilizing a bilayer film PEDOT-0.2C/PPY-0.3C. Further FTIR and UV–Vis spectra show that the bilayer films are successfully formed and both polymers play a role in the electrochemical process. Different morphologies of bilayer films with reverse positions observed by SEM images account for the correlation between the infrared regulation performance and deposition sequence.