<p>In the current study graphene oxide (GO) as a novel approach was examined to reduce the optical bandgap of polyvinyl alcohol (PVA). The synthesis of PVA/GO nanocomposite films with varying GO concentrations was conducted using solution cast procedure. The PVA/GO composites were studied by XRD, FTIR and SEM to understand the structural and morphological appearance. A comprehensive optical characterization was performed using UV–Vis spectroscopy. Dispersion parameters were analyzed using the Wemple and DiDomenico (WDD) model, which showed that GO material had a major impact on the films' optical performance. The observed significant variations in the dispersion energy (<InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10854_2025_15127_Article_IEq1.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="21" /> </InlineMediaObject> <EquationSource Format="TEX">$E_{{\text{d}}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>E</mi> <mtext>d</mtext> </msub> </math></EquationSource> </InlineEquation>), the high-frequency dielectric constant (<InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10854_2025_15127_Article_IEq2.gif" Format="GIF" Height="12" Rendition="HTML" Resolution="72" Type="Linedraw" Width="23" /> </InlineMediaObject> <EquationSource Format="TEX">$\varepsilon_{\infty }$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>ε</mi> <mi>∞</mi> </msub> </math></EquationSource> </InlineEquation>), and the single-effective oscillator energy (<InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10854_2025_15127_Article_IEq3.gif" Format="GIF" Height="16" Rendition="HTML" Resolution="72" Type="Linedraw" Width="20" /> </InlineMediaObject> <EquationSource Format="TEX">$E_{0}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>E</mi> <mn>0</mn> </msub> </math></EquationSource> </InlineEquation>) are of great interest. Drude's theory was also used to investigate the dielectric characteristics; the results showed variations in the free carrier concentration and lattice dielectric constants (<InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10854_2025_15127_Article_IEq4.gif" Format="GIF" Height="12" Rendition="HTML" Resolution="72" Type="Linedraw" Width="17" /> </InlineMediaObject> <EquationSource Format="TEX">$\varepsilon_{{\text{L}}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>ε</mi> <mtext>L</mtext> </msub> </math></EquationSource> </InlineEquation>). The investigation also focused on nonlinear optical properties, emphasizing improvements in nonlinear susceptibilities (<InlineEquation ID="IEq5"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10854_2025_15127_Article_IEq5.gif" Format="GIF" Height="20" Rendition="HTML" Resolution="72" Type="Linedraw" Width="28" /> </InlineMediaObject> <EquationSource Format="TEX">$\chi^{\left( 1 \right)}$</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>χ</mi> <mfenced close=")" open="("> <mn>1</mn> </mfenced> </msup> </math></EquationSource> </InlineEquation> and <InlineEquation ID="IEq6"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10854_2025_15127_Article_IEq6.gif" Format="GIF" Height="20" Rendition="HTML" Resolution="72" Type="Linedraw" Width="28" /> </InlineMediaObject> <EquationSource Format="TEX">$\chi^{\left( 3 \right)}$</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mi>χ</mi> <mfenced close=")" open="("> <mn>3</mn> </mfenced> </msup> </math></EquationSource> </InlineEquation>) and nonlinear refractive indices (<InlineEquation ID="IEq7"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10854_2025_15127_Article_IEq7.gif" Format="GIF" Height="12" Rendition="HTML" Resolution="72" Type="Linedraw" Width="18" /> </InlineMediaObject> <EquationSource Format="TEX">$n_{2}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>n</mi> <mn>2</mn> </msub> </math></EquationSource> </InlineEquation>) at higher concentrations of GO. The findings demonstrate that GO doping efficiently tailors the optical and dielectric properties of PVA-based materials, making them suitable for a variety of optoelectronic applications. </p>

Structural, morphological, and optical properties of PVA polymer composites incorporated with various concentrations of GO: linear and nonlinear optoelectronic studies

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发表日期：

2025年6月21日

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Siyamand S. Khasraw,
Dyari M. Mamand,
Salah R. Saeed,
Abdollah Hassanzadeh,
Omed Gh. Abdullah,
Shujahadeen B. Aziz

摘要

In the current study graphene oxide (GO) as a novel approach was examined to reduce the optical bandgap of polyvinyl alcohol (PVA). The synthesis of PVA/GO nanocomposite films with varying GO concentrations was conducted using solution cast procedure. The PVA/GO composites were studied by XRD, FTIR and SEM to understand the structural and morphological appearance. A comprehensive optical characterization was performed using UV–Vis spectroscopy. Dispersion parameters were analyzed using the Wemple and DiDomenico (WDD) model, which showed that GO material had a major impact on the films' optical performance. The observed significant variations in the dispersion energy ( $E_{{\text{d}}}$ $E_{d}$ ), the high-frequency dielectric constant ( $\varepsilon_{\infty }$ $ε_{\infty}$ ), and the single-effective oscillator energy ( $E_{0}$ $E_{0}$ ) are of great interest. Drude's theory was also used to investigate the dielectric characteristics; the results showed variations in the free carrier concentration and lattice dielectric constants ( $\varepsilon_{{\text{L}}}$ $ε_{L}$ ). The investigation also focused on nonlinear optical properties, emphasizing improvements in nonlinear susceptibilities ( $\chi^{\left( 1 \right)}$ $χ^{(1)}$ and $\chi^{\left( 3 \right)}$ $χ^{(3)}$ ) and nonlinear refractive indices ( $n_{2}$ $n_{2}$ ) at higher concentrations of GO. The findings demonstrate that GO doping efficiently tailors the optical and dielectric properties of PVA-based materials, making them suitable for a variety of optoelectronic applications.