Transmissive to Dark Electrochromic and Fluorescent Device Based on Poly(fluorene-bisthiophene) Derivative

Abstract

Films of a poly(fluorene-bisthiophene) derivative, named PFBT, were electrodeposited onto indium tin oxide (ITO) electrodes and their electrochromic and fluorescence properties were investigated. Such films displayed color variation from yellow, in the neutral state, to green, in the oxidized state, as shown by tracking of the CIE (Commission Internationale de l'Eclairage) 1931 xy chromaticity coordinates. PFBT films are fluorescent in the neutral state (E = 0.0 V vs. Ag/Ag +) with emission at 532 nm; however, upon oxidation at 0.85 V the photoluminescence intensity is significantly decreased. A solid-state electrochromic device was assembled using PFBT and poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT-PSS) films and a polymer electrolyte. The device presented color variation from transmissive greenish-yellow to blue and reversible fluorescent properties upon switching between −1.5 to 1.5 V vs. PEDOT. Thus, the high contrast and stability both in electrochromism and electrofluorescence of the PFBT film and its device make them suitable for application in multifunctional optical devices.

A low‐potential electrochemical method for fast development of latent fingerprints on brass cartridge cases by electrodeposition of poly(3,4‐ethylenedioxythiophene)

“…Taking advantage of the electrochemical processes that can occur on metallic surfaces, the electrodeposition of conjugated polymers, such as polypyrrole (PPy), polyaniline (PAni) and poly(3,4-ethylenedioxythiophene) (PEDOT), for enhancement of latent fingerprints on stainless steel or brass plates was firstly reported by Bersellini et al [19] and Hillman et al [20][21][22] According to this approach, our research group has been working with a series of conjugated polymer derivatives for different applications, [23][24][25] including forensic purposes. [26,27] Recently, Costa et al [26,27] have demonstrated a strategy for fluorescence development of latent fingerprints on stainless steel consisting in a bilayer of electrodeposited conjugated polymers with excellent results.…”

From nanomaterials to macromolecules: Innovative technologies for latent fingerprint development

“…The end result of the above is electronic and spectral features that respond to modifications of the chemical structure, including variation in emission wavelength, absorption in the visible region, and electrochemical response (Beaujuge & Reynolds, 2010; Ribeiro & Mortimer, 2016; Roncali, 1997). Due to their electrical, magnetic and optical properties, conjugated polymers have found application as the active materials in organic optoelectronic devices, such as electrochromic devices (Neto et al, 2020; Nogueira et al, 2019), solar cells (Rech et al, 2021), organic light emitting diodes (OLEDs) (Yang et al, 2018) and fluorescent sensors (Wang et al, 2020).…”