<p>The present study deals with the synthesis and characterization of transparent and conducting <InlineEquation ID="IEq1"> <EquationSource Format="TEX">$\textrm{Zn}_{1-x}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mtext>Zn</mtext> <mrow> <mn>1</mn> <mo>-</mo> <mi>x</mi> </mrow> </msub> </math></EquationSource> </InlineEquation> <InlineEquation ID="IEq2"> <EquationSource Format="TEX">$\textrm{Cu}_{x}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mtext>Cu</mtext> <mi>x</mi> </msub> </math></EquationSource> </InlineEquation>S thin films at <InlineEquation ID="IEq3"> <EquationSource Format="TEX">$x = 0.00, 0.03, 0.05,$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>x</mi> <mo>=</mo> <mn>0.00</mn> <mo>,</mo> <mn>0.03</mn> <mo>,</mo> <mn>0.05</mn> <mo>,</mo> </mrow> </math></EquationSource> </InlineEquation> & 0.07 and studied the effect of Cu on the physical properties of the thin films. The thin films were prepared by the thermal evaporation technique. The properties of the films were investigated by advanced characterization techniques, and found that these properties are best suited for optoelectronic applications. The structural, morphological, elemental, surface roughness, topographical, optical, and electrical properties were studied by XRD, SEM, EDAX, AFM, UV–Vis spectroscopy, photoluminescence (PL), Hall effect measurements, and I–V measurements, respectively. The XRD patterns confirmed the cubic structure of the <InlineEquation ID="IEq4"> <EquationSource Format="TEX">$\textrm{Zn}_{1-x}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mtext>Zn</mtext> <mrow> <mn>1</mn> <mo>-</mo> <mi>x</mi> </mrow> </msub> </math></EquationSource> </InlineEquation> <InlineEquation ID="IEq5"> <EquationSource Format="TEX">$\textrm{Cu}_{x}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mtext>Cu</mtext> <mi>x</mi> </msub> </math></EquationSource> </InlineEquation>S thin films. The surface morphology of the thin films was analysed using SEM and AFM analysis. The SEM micrographs reflects the role of Cu on the growth mechanisms of the <InlineEquation ID="IEq6"> <EquationSource Format="TEX">$\textrm{Zn}_{1-x}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mtext>Zn</mtext> <mrow> <mn>1</mn> <mo>-</mo> <mi>x</mi> </mrow> </msub> </math></EquationSource> </InlineEquation> <InlineEquation ID="IEq7"> <EquationSource Format="TEX">$\textrm{Cu}_{x}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mtext>Cu</mtext> <mi>x</mi> </msub> </math></EquationSource> </InlineEquation>S thin films. The RMS roughness of the thin films decreased from 5.37 to 3.50 nm with the dopant concentration. The EDAX spectra confirmed the existence of host (Zn, S) and dopant (Cu) elements in nearly stoichiometric ratios. The optical properties, such as optical absorbance and transmittance, were recorded using a UV–Vis-NIR spectrophotometer, and the optical band gap was calculated using Tauc’s relation. The optical band gap decreased from 3.41 to 3.29 eV with an increase of Cu concentration. From the PL spectra, it was observed that the intensity of the emission peaks decreased with the increase of Cu concentration and it indicating the decrease in defects with doping concentrations. The light and dark currents were studied using current versus voltage (I–V) characteristics. The electrical properties of the films were studied using Hall measurements and observed conversion of the films from n-type semiconducting nature to p-type semiconducting nature with Cu concentration. The electrical conductivity of the films increased with the increase of Cu concentration. The films exhibited higher electrical conductivity at higher Cu concentration.</p>

Transparent, N to P-type transition of thermally evaporated Cu-doped ZnS thin films for optoelectronic device applications

期刊论文
发表日期：

2025年8月7日

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Ravi Sankar Reddy Mummadi,
Kaleemulla Shaik

摘要

The present study deals with the synthesis and characterization of transparent and conducting $\textrm{Zn}_{1-x}$ ${Zn}_{1 - x}$ $\textrm{Cu}_{x}$ ${Cu}_{x}$ S thin films at $x = 0.00, 0.03, 0.05,$ $x = 0.00, 0.03, 0.05,$ & 0.07 and studied the effect of Cu on the physical properties of the thin films. The thin films were prepared by the thermal evaporation technique. The properties of the films were investigated by advanced characterization techniques, and found that these properties are best suited for optoelectronic applications. The structural, morphological, elemental, surface roughness, topographical, optical, and electrical properties were studied by XRD, SEM, EDAX, AFM, UV–Vis spectroscopy, photoluminescence (PL), Hall effect measurements, and I–V measurements, respectively. The XRD patterns confirmed the cubic structure of the $\textrm{Zn}_{1-x}$ ${Zn}_{1 - x}$ $\textrm{Cu}_{x}$ ${Cu}_{x}$ S thin films. The surface morphology of the thin films was analysed using SEM and AFM analysis. The SEM micrographs reflects the role of Cu on the growth mechanisms of the $\textrm{Zn}_{1-x}$ ${Zn}_{1 - x}$ $\textrm{Cu}_{x}$ ${Cu}_{x}$ S thin films. The RMS roughness of the thin films decreased from 5.37 to 3.50 nm with the dopant concentration. The EDAX spectra confirmed the existence of host (Zn, S) and dopant (Cu) elements in nearly stoichiometric ratios. The optical properties, such as optical absorbance and transmittance, were recorded using a UV–Vis-NIR spectrophotometer, and the optical band gap was calculated using Tauc’s relation. The optical band gap decreased from 3.41 to 3.29 eV with an increase of Cu concentration. From the PL spectra, it was observed that the intensity of the emission peaks decreased with the increase of Cu concentration and it indicating the decrease in defects with doping concentrations. The light and dark currents were studied using current versus voltage (I–V) characteristics. The electrical properties of the films were studied using Hall measurements and observed conversion of the films from n-type semiconducting nature to p-type semiconducting nature with Cu concentration. The electrical conductivity of the films increased with the increase of Cu concentration. The films exhibited higher electrical conductivity at higher Cu concentration.