Investigation of the doping mechanism and electron transition bands of PEO/KMnO4 complex composite films

Abstract

Polyethylene oxide (PEO) incorporated with potassium permanganate (KMnO4) was prepared using the solution casting technique forming PEO/KMnO4 complex composite films. The physicochemical properties, doping mechanism, and electron transition bands of PEO/KMnO4 were investigated. Introducing KMnO4 PEO matrix led to a decrease in crystallinity degree and optical bandgap energy due to the creation of polarons and bipolarons that form new energy levels in the bandgap between the HOMO and LUMO; in addition, to form of a new transition band appears at about 380 nm is attributed to the $$n{-}{\pi }^{*}$$ n - π ∗ electronic transitions are generated due to the unsaturated center of the molecules. The existence of KMnO4 in the polymer matrix leads to the blocking of light in the 250–400 nm range. Consequently, PEO/KMnO4 complex composite films could be used as UV-light shielding filters. Furthermore, the electrical conductivity of the PEO/KMnO4 complex composite films increases as KMnO4 concentration is increased in the PEO matrix since the created new energy levels in the bandgap between the HOMO and LUMO can be populated with conduction electrons providing true ohmic conduction with the delocalization of the electron densities moving on the polymer chain.

Optical and electrical properties of polyethylene oxide‐poly(3,4‐ethylenedioxythiophene)/NiZnFeO4 NPs nanocomposite films

“…7,22 In addition, the C -O -C stretching band of PEO and PEDOT appears at 1093 cm À1 , indicating the semicrystalline phase of PEO. 24 Incorporating NiZnFeO 4 NPs with PEO-PEDOT change the intensity and the linewidth of the C -O -C stretching vibrational band and, consequently, indicate the changing of crystallinity degree of PEO À PEDOT=NiZnFeO 4 NPs nanocomposites as a variation of NiZnFeO 4 NPs concentrations. In addition, shallow vibration bands show up between 400 and 500 cm À1 represent NiZnFeO 4 NPs existence in the polymer matrix of PEO À PEDOT.…”

“…All nanocomposites spectra exhibit vibration bands of PEO and/or PEDOT (Figure 1), that is, stretching (at ), scissoring (at ), wagging (1342 cm −1 ), twisting ( and ), and stretching C − S − C (at 530 cm −1 ) 7,22 . In addition, the stretching band of PEO and PEDOT appears at 1093 cm −1 , indicating the semicrystalline phase of PEO 24 . Incorporating with PEO‐PEDOT change the intensity and the linewidth of the stretching vibrational band and, consequently, indicate the changing of crystallinity degree of nanocomposites as a variation of concentrations.…”

“… possess unique properties, including high magnetic moment, excellent catalytic activity, and high electrical conductivity, which make them highly suitable for various applications 18,19 . Polyethylene oxide (PEO) is a polymer electrolyte with superior physicochemical characteristics, 20 such as easy fabrication as solid films, high solubility in organic solvents, 21 ability to dissociate ions and dissolve ionic salts, 22,23 semiconducting properties with low electrical conductivity, 24 and semicrystalline nature 25,26 . When conductive polymers are incorporated with semiconductor NPs hosted in PEO film matrix, they can be utilized in various optoelectronic applications, such as field‐effect transistors (OFETs), light‐emitting diodes (OLEDs), and photovoltaic cells (OPVs) 27 …”

Surface Plasmon Resonance Sensitivity Enhancement Based on Protonated Polyaniline Films Doped by Aluminum Nitrate

“…All the films exhibited two bandgap energies; the first band-gap energy ( E g1 ) decreased from 3.40 eV to 3.01 eV, representing the π-π* electron transition within the benzenoid (B) ring, while the second bandgap energy ( E g2 ) decreased from 2.45 eV to 2.24 eV, representing localized polarons (polaron-π*) (quinoid, Q) electron transition ( Figure 6 e). The decrease in the bandgap energies as increasing Al(NO 3 ) 3 can be attributed to generating new energy levels between the HUMO and LOMO because of the disorder in the structure of the composite films [ 55 ]. Urbach energy, E U is considered an essential method for studying the degree of disorder in films, which is calculated using α = α 0 exp( hν / E U ), where: α 0 is a constant [ 56 , 57 ].…”

Hidden impurities in transparent conducting oxides: study of vacancies-related defects and impurities in (Cu–Ni) co-doped ZnO films

“…The electrical conductivity of metal oxide films depends on many parameters, such as dopant type, dopant concentration, impurities, and crystallinity degree [43]. The asprepared film has an average conductivity of 2.93 ± 0.2 μS/ cm, while the annealed film under air vacuum, nitrogen, and argon atmospheres has average electrical conductivities of 3.77 ± 0.2, 6.71 ± 0.2, 6.48 ± 0.2, and 6.80 ± 0.2 μS/cm, respectively (Fig.…”