In this article, the authors are presented the work on the evaluation of structural and third-order nonlinear optical (NLO) properties of lead (Pb)-doped zinc oxide (ZnO) thin films. The nano ...structured Zn
1-x
Pb
x
O thin films were lay down on the glass substrate at an heating temperature of 350 °C with different Pb-doping concentration (‘x’ ratios of 0, 0.01, 0.05 and 0.1 wt. % of Pb) using the standard spray pyrolysis technique. The powder X-ray diffraction (P-XRD) spectroscopic analysis reveals the polycrystalline existence in the lead doped thin films in evidence with the hexagonal structure. The reformed grain sizes with enhanced doping content was perceived through surface morphological analysis with the help of field emission scanning electron microscopy and are in line with the X-Ray diffraction observations. The upgraded optical band gaps (Eg) were inferred through UV–Vis spectroscopic studies for the tailored films from 3.21 eV (pure ZnO) to 3.34 eV (10 wt. % of Pb). The defect states appearances and photoluminescence properties are discussed for the fabricated thin films using the resulted room temperature photoluminescence (RTPL) spectroscopic data. The third-order NLO parameters were calculated by potentially exposing the prepared thin films to the z-scan analysis under a continuous wave solid state laser at an excitation wavelength of 532 nm. The reverse saturable absorption, excited state absorption and self-defocusing effects were observed from the z-scan test along with the elevated nonlinear absorption coefficient (β) from 4.74 × 10
–4
to 1.05 × 10
–3
(cm/W) and negative nonlinear refractive index
(
n
2
) from 1.42 × 10
–8
to 5.60 × 10
–8
(cm
2
W
−1
). In addition to this, the third-order NLO susceptibility (χ
(3)
) values are also calculated and are augmented from 0.82 × 10
–5
to 1.45 × 10
–4
(esu). An optical limiting (OL) topography with the limiting thresholds was also explored at the experimental wavelength. Hence, the outcome of structural, linear and nonlinear optical studies acknowledged the ability of the Zn
1-x
Pb
x
O thin films in the field of optoelectronic device applications.
The present work reports the study on effect of annealing at different temperature and dissimilar Cd/Zn ratios on optical linear and nonlinear properties of Cd
1-x
Zn
x
S (in
x
ratios of = 0.00, ...0.01, 0.03, 0.05 and 0.1 wt. % of Zn) thin films deposited by spray pyrolysis (SP) technique. All the fabricated films are polycrystalline in nature and having a hexagonal crystal structure with the single phase of CdS was confirmed by Powder X-ray diffraction studies (P-XRD). The Scherer rule was used to assess the size of the crystallite and was found to be increasing with increasing annealing temperature. FESEM images display uniform grains and decrease marginally with an increase in doping content and annealing. The optical energy band gap (Eg) of the prepared films ranged from 2.40 eV to 2.64 eV. The laser-induced damage threshold (LDT) value of the annealed Cd
1-x
Zn
x
S thin film is 0.1520 KW/cm
2
. The NLO parameters of the prepared samples were calculated at 532 nm from the Z-scan data under solid state continuous wave laser irradiation and the 3rd-order NLO components such as β,
n
2
and χ
(3)
were found to be enhanced with the annealing temperature i.e. from 1.58 × 10
−5
to 4.85 × 10
−3
(cmW
−1
), 1.08 × 10
−8
to 4.38 × 10
−8
(cm
2
W
−1
) and 7.22 × 10
−7
to 5.94 × 10
−6
(esu) respectively. These favourable results of NLO parameters suggests, the current fabricated nanstructured films are capable material for photonic device applications.
The work presented here reported the thickness dependent structural, linear and nonlinear optical properties of nanostructured Cd
1−
x
Zn
x
O thin films. Thin films were prepared with two different ...thickness (≈ 0.5 µm and 1 µm) by employing a spray pyrolysis (SP) technique for different Zn-doping levels (Cd
1−
x
Zn
x
O with the
x
value of 0.00, 0.01, 0.05 and 0.1). X-ray diffraction studies confirm the polycrystalline nature having a cubic crystal structure. In terms of an aspect ratio of the columnar structure and dispersion in hexagonal (1 1 1) basal plane orientation, a thickness dependency of structural evolution was discussed. The Scherrer rule was employed to determine the crystallite size and found to be decreased. FESEM images indicate grains which are uniform and grain size slightly increased with an increase in dopant concentration, annealing and thickness of the films, respectively. The optical energy band gap (
E
g
) of the prepared films was found to be increased from 2.50 to 2.67 eV. The NLO parameters of the samples were measured from the Z-scan data under DPSS continuous wave laser excitation at 532 nm and the results reveal that reverse saturable absorption (RSA) and self-defocusing natures are the attributed and observed nonlinearity of the nanostructures. The third-order NLO components such as
β
,
n
2
and
χ
(3)
are found to be enhanced with one order of magnitude higher with the influence of thickness from 1.25 × 10
–4
to 2.47 × 10
–3
(cm W
−1
), 7.08 × 10
–9
to 3.35 × 10
–8
(cm
2
W
−1
) and 4.06 × 10
–7
to 1.96 × 10
–6
(esu) respectively. The inspiring results of NLO parameters are also due to the increasing localized defect states on grain boundaries as the film thickness increases, suggesting the prepared films are a promising material for nonlinear photonic device applications.
In this work, Chromium (Cr) doped Zinc Oxide (ZnO) nano-structured thin films were deposited using ultrasonic spray pyrolysis technique on glass substrate at different concentration (0,1,3,5,10 wt%) ...with a substrate temperature of 350
o
C. The effect of chromium on zinc oxide thin films was studied to extract the structural, optical and electrical characteristics using XRD, UV-Vis spectroscopy and Hall effect measurement instruments respectively. The work on undoped ZnO showed hexagonal wurtzite structure, with an ideal orientation of (101). The increase in strain with respect to doping concentration confirmed decrease in the crystallite size. Variation in the surface roughness on doping Cr is observed. The optical results depicted influence of Cr doping resulted in the decrease in transmittance. Band-gap (BG) obtained using Tauc’s plot was seen to vary with Cr-doping. Hall effect measurement at standard conditions observed decreases in carrier concentration, and indicating the conduction to be n-type. The study of third-order nonlinear optical characteristics, such as susceptibility χ
(3)
, nonlinear refractive index (NRI) (𝑛
2
), and nonlinear absorption coefficient (β) was carried out. These findings suggest that the films consist of self-defocusing nonlinearity. The overall results confirmed that the structural and optical results were dependent on Cr concentration in ZnO.
Cobalt (Co)-doped CdS thin films were deposited and successfully grown by the chemical reactive spray pyrolysis technique with different Co-doping levels (Cd
1−
x
Co
x
S) in ‘
x
’ ratios of 0.00, ...0.01, 0.05 and 0.1 wt% on heated glass substrates at 350 °C. The effect of Co content on nonlinear optical (NLO) properties was investigated by the DPSS continuous wave laser at 532 nm using the
Z
-scan technique. Powder-XRD analysis confirms the samples that have cubic structure with no impurity phases. The energy gap (
E
g
) of the prepared films was estimated and was found to be decreased by 2%, i.e., in the range from 2.50 to 2.30 eV. The room-temperature photoluminescence spectra were recorded at
λ
exc = 275 nm and an intense blue emissions were observed at 430 ± 15 nm for undoped CdS and Co:CdS films. The
Z
-scan result reveals that reverse saturable absorption and self-defocusing nature are the attributed and observed nonlinearity of the prepared nanostructures. The nonlinear absorption coefficient, refractive index and third-order NLO susceptibility were determined and found in the range from 1.89 × 10
−3
to 7.26 × 10
−3
(cm W
−1
), 2.03 × 10
−8
to 2.96 × 10
−8
(cm
2
W
−1
) and 1.21 × 10
−6
to 6.95 × 10
−6
(esu) correspondingly. An optical limiting topographies of the prepared films were explored and the limiting thresholds are also calculated at the experimental wavelength. These important results of NLO parameters are due to the increase in localized defect states on grain boundaries with the increase in Co-doping and suggest that these films are promising material for optoelectronic device applications.
In this paper, we report enhancing the structural, morphological, mechanical, linear and nonlinear optical properties of polyvinyl alcohol (PVA) encapsulated with titanium dioxide (TiO2) and copper ...oxide (CuO) nanoparticles. PVA/(x)TiO2(15-x)CuO nanocomposites for x = 0 wt%, 1 wt%, 5 wt%, 7.5 wt%, 10 wt%, 14 wt% and 15 wt% filling concentration are prepared using ex-situ and solvent casting technique. The XRD spectra of the prepared nanocomposites endorse the semi-crystalline nature of PVA nanocomposites. The atomic force microscope (AFM) image displayed the uniform grain structure for pure PVA and change in surface morphology for prepared nanocomposites. Universal testing machine (UTM) explored high tensile strength and Young's modulus of 1685.70 MPa for x = 10 wt% filling concentration. PVA/(x)TiO2(15-x)CuO nanocomposites shows an enhanced electrical conductivity of 3.21 × 10−8Scm−1 for x = 10 wt% filling concentration. UV–Vis spectroscopy exposed the reduction in optical energy gap with the increase in filling concentration. Photoluminescence (PL) studies spectacles maximum enhancement in PL intensity for x = 10 wt% filling concentration. The Z-scan technique shows third order nonlinear absorption coefficient of 8.17 × 10−4 cm/W, the nonlinear refractive index of 2.56 × 10−8 cm2/W and nonlinear optical susceptibility of 1.48 × 10−6 esu for optimum nanocomposites.
•XRD spectra confirm the formation of semi crystalline nature of the nanocomposites.•PL studies shows an intense emission band at 680 nm resemble the electron hole recombination of TiO2 and CuO nanoparticles.•Dielectric studies exposes the maximum real dielectric constant value 7.5 for x = 10 wt% filling concentration.•NLO studies show material exhibit strong two-photon absorption and high third order Non-linear optical susceptibility.
In the current work, the authors aim to present an insight on the role of cobalt (Co) doping for the structural, morphological, and linear and nonlinear optical (NLO) properties of CdO thin films. ...The films were prepared using the spray pyrolysis (SP) technique, and the weight % of Co (x) was varied from 0–10. The structural properties of the films were confirmed by the powder X-ray diffraction (P-XRD) studies and are polycrystalline with a cubic structure and a lattice parameter of 0.4658 nm. As Co content in CdO films increases, cluster grain size and porosity decrease significantly, as seen in surface topographic and nanostructural analysis. Through the Burstein–Moss shift, the optical band gap “Eg” in Co: CdO film decreases from 2.52 to 2.05 eV with the increase in Co-doping. To study the NLO parameters, open aperture (OA) and closed aperture (CA) Z-scan measurements were performed using the diode-pumped solid-state continuous wave laser excitation (532 nm), and with the increased Co-content, the NLO parameters—nonlinear absorption coefficient (β∼10−3 cm/W), nonlinear refractive index n2 ∼10−8 cm2/W), and the 3rd-order NLO susceptibility χ3∼10−7 to 10−6 e.s.u.) values were determined and found to be enhanced. The maximum NLO parameters achieved in the present study with increasing Co concentration on CdO nanostructures prepared by the SP method are found to be the highest among the reported values and suggest that processed films are a capable material for optoelectronic sensor applications.
A noncentrosymmetric chalcone derivative (E)-1-(thiophen-2-yl)-3-(3, 4, 5-trimethoxyphenyl) prop-2-en-1-one (TTMP) was synthesized using Claisen Schmidt condensation approach and single crystals were ...grown using slow evaporation method. The grown TTMP crystals crystallizes in orthorhombic structure with Pna21 space group. The intermolecular interactions of the TTMP crystals were envisioned by Hirshfeld surface analysis (HSA). Further, the structural conformations of the crystal were carried out by using 1H NMR, FTIR, and FT-Raman spectral analysis. The UV–Vis–NIR spectrum of the sample clearly shows the prime transparency in the entire visible and near infrared region. Thermal studies (TG/DTA/DSC) of the TTMP sample shows excellent thermal stability and phase transition and also noticed that crystal was most stable up to 152.65 °C. The second harmonic generation efficiency was obtained for the crystals using Nd:YAG laser and is to be 1.93 times that of urea. The third order nonlinear absorption coefficient (β), nonlinear refractive index (n2), third-order nonlinear susceptibilities (χ (3)), second order hyper polarizability (γh) and optical limiting thresholds were determined by Z-scan technique using the Diode-Pumped Solid State (DPSS) Continuous Wave (CW) laser. The results suggest that the TTMP molecules are promising materials for optoelectronic device applications.
•2-acetyl thiophene and 3,4,5 trimethoxy benzaldehyde were used for synthesis.•Thermal properties were studied using DSC/ TG/DTA Analysis.•Nonlinear absorption (NLA) coefficients (β ~ 10-6 cmW-1).•Nonlinear refractive index (NRI) (n2 ~10-10cm2W-1).•Third-order NLO susceptibilities (χ(3) ~10-7 esu) were determined.
•Cd1-xPbxS (x = 0.00, 0.01, 0.05 and 0.1 wt.% of Pb) nanostructures was fabricated by the thermal evaporation (PVD) technique.•The effect of Pb-doping on the key physical properties of CdS thin films ...were studied.•The morphology and surface topography of the films were largely influenced by the Pb-doping.•Nanostructure exhibits excellent two photon absorption (β) and third order susceptibility (χ(3)) under pulse laser excitation.
A polycrystalline nanostructured cadmium lead sulfide thin film was deposited using the thermal evaporation (PVD) technique (Cd1-xPbxS with x = 0.00, 0.01, 0.05 and 0.1 wt.% of Pb). Structural parameters of as-prepared Cd1-xPbxS thin films have been studied through X-ray diffraction. The optical investigation demonstrates that Cd1-xPbxS film's optical band gap (Eg) may be adjusted from the visible to the near-infrared region. (2.64 - 2.42 eV). The film is substantially more appropriate for absorbing layers in solar cells and optoelectronic applications due to the large decrease in ‘Eg.’ The enhanced Pb doping was found to have altered the surface morphology, verified by Field Emission Scanning Electron Microscopy (FESEM) images. The doped films also showed a significant red shift in the band edge and increased transmittance in the visible and NIR regions. The third-order nonlinear optical (TONLO) parameters of the samples were determined from the Q-switched Nd: YAG laser with 65-ps pulse duration at 1064 nm. The investigated TONLO components such as nonlinear absorption coefficient (β), nonlinear refractive index (n2) and the susceptibility χ(3)were found to be in the range from 1.16 × 10−3 to 4.12 × 10−3 (cmW−1), 1.06 × 10−8 to 3.32 × 10−8 (cm2 W−1) and 1.23 × 10−4 to 5.62 × 10−4 (esu) respectively. The results indicate that Pb-doping on CdS nanostructures on surface morphology can be used to modify NLO characteristics.Cd1-xPbxS thin film is a potential and able material for optoelectronic device applications, as seen by these encouraging NLO results.
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