STRUCTURE AND OPTICAL PROPERTIES OF NANOCRYSTALLINE ERBIA DOPED ZIRCONIA THIN FILMS

2000 ◽  
Vol 14 (11) ◽  
pp. 1239-1248 ◽  
Author(s):  
A. HARTRIDGE ◽  
M. GHANASHYAM KRISHNA ◽  
A. K. BHATTACHARYA
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Dopant Concentration ◽  
Sol Gel ◽  
Fluorite Structure ◽  
X Ray Diffraction ◽  
A Value ◽  
Crystallite Sizes ◽  
Quartz Substrates ◽  
Similar Peak

Thin films of zirconia doped with erbia in the concentration range of 5 to 15% have been prepared on quartz substrates by an inorganic and aqueous sol–gel method. The films were crystalline, continuous and single phase as deposited, with a cubic fluorite structure and crystallite sizes of 8–10 nm as shown by X-ray diffraction. The films were annealed to 600 and 1050°C after deposition and found to be transparent in the region between 400 to 1100 nm, the crystalline structure becoming tetragonal at 1050°C with crystallite sizes of around 30–40 nm. The refractive index increased with increase in annealing temperature. There is a peak in the refractive index at a dopant concentration of 10% where it achieves a value of 1.88 at 700 nm. The optical absorption edge shows a similar peak at the same dopant concentration with a value of 5.65 eV.

OPTICAL PROPERTIES OF NANOCRYSTALLINE YTTERBIA DOPEDC ZIRCONIA THIN FILMS

2000 ◽  
Vol 14 (09) ◽  
pp. 1017-1024
Author(s):  
A. HARTRIDGE ◽  
M. GHANASHYAM KRISHNA ◽  
A. K. BHATTACHARYA
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Annealing Temperature ◽  
Optical Band Gap ◽  
Dopant Concentration ◽  
Sol Gel ◽  
Fluorite Structure ◽  
Optical Losses ◽  
Cubic Structure ◽  
Quartz Substrates

Thin films of Zr 1-x Yb x O 2-y where x ranges from 0 to 0.3 have been coated onto quartz substrates using an inorganic sol–gel approach at low temperature. The films were fully crystalline and continuous as deposited, with a fluorite structure. On heating over 900°C, films with less than 16% doping had a tetragonal structure whilst those above retained a cubic structure. Crystallite size measurements indicated that the films were nanocrystalline, the size decreasing as a function of increasing dopant concentration. The films are transparent in the region 500 to 1500 nm with very low optical losses. The film refractive index seems relatively independent of the dopant concentration. The optical band gap is dependent on the dopant concentration and is in the range 5.6 to 5.7 eV. There is an increase in refractive index and decrease in optical absorption with increase in annealing temperature from 600°C to 1050°C.

scholarly journals Structural and optical properties of pure and Ag doped ZnO thin films obtained by sol gel spin coating technique

2015 ◽  
Vol 33 (3) ◽  
pp. 601-605 ◽  
Author(s):  
Syed Mansoor Ali ◽  
W. A. Farooq ◽  
M. R. Baig ◽  
M.A. Shar ◽  
M. Atif ◽  
...  
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Band Gap ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Oxide Thin Films ◽  
Ag Doping ◽  
Crystallite Sizes ◽  
Transmission Measurements ◽  
Ion Incorporation

Abstract We have investigated the influence of Ag doping on zinc oxide thin films. Pure and Ag doped, preferentially oriented transparent zinc oxide thin films were prepared by sol gel technique on a glass substrate using diethyl amine as a stabilizer. The X-ray diffraction analysis revealed that the films with hexagonal wurtzite type structure were polycrystalline in nature with a preferred grain orientation in the 101 direction. The crystallite sizes decreased from 34 nm to 27 nm after silver doping. Both photoluminescence and optical transmission measurements showed that the band gap increased after the Ag doping. The structure and optical characterization studies clearly indicated the incorporation of Ag in ZnO. Hence, the observed increase in the optical band gap and decrease in crystallite size can be directly attributed to the effect of Ag ion incorporation into the ZnO lattice.

High Transmission and Low Resistivity Cadmium Tin Oxide Thin Films Deposited by Sol-Gel

2014 ◽  
Vol 1675 ◽  
pp. 151-156 ◽  
Author(s):  
Carolina. J. Diliegros Godines ◽  
Rebeca Castanedo Pérez ◽  
Gerardo Torres Delgado ◽  
Orlando Zelaya Ángel
Keyword(s):  
Thin Films ◽  
Tin Oxide ◽  
Sol Gel ◽  
Dip Coating ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Corning Glass ◽  
Vacuum Atmosphere ◽  
Xrd Patterns ◽  
Quartz Substrates

ABSTRACTTransparent conducting cadmium tin oxide (CTO) thin films were obtained from a mixture of CdO and SnO2 precursor solutions by the dip-coating sol-gel technique. The thin films studied in this work were made with 7 coats (∼200 nm) on corning glass and quartz substrates. Each coating was deposited at a withdrawal speed of 2 cm/min, dried at 100°C for 1 hour and then sintered at 550°C for 1 hour in air. In order to decrease the resistivity values of the films, these were annealed in a vacuum atmosphere and another set of films were annealed in an Ar/CdS atmosphere. The annealing temperatures (Ta) were 450°C, 500°C and 550°C, as well as 600°C and 650°C, when corning glass and quartz substrates were used, respectively. X-Ray diffraction (XRD) patterns of the films annealed in a vacuum showed that there is only the presence of CTO crystals for 450°C≤ Ta ≤ 600°C and CTO+SnO2 crystals for Ta=650°C. The films annealed in Ar/CdS atmosphere were only constituted of CTO crystals independent of the Ta. The minimum resistivity value obtained was ∼4 x 10-4 Ωcm (Rsheet= 20 Ω/□) for the films deposited on quartz and annealed at Ta=600°C under an Ar/CdS atmosphere. The films deposited on quartz showed the higher optical transmission (∼90%) with respect to the films deposited on corning glass substrates (∼85%) in the Uv-vis region. For their optical and electrical characteristics, these films are good candidates as transparent electrodes in solar cells.

scholarly journals Synthesis, Giant Dielectric, and Pyroelectric Response of [001]-Oriented Pr3+ Doped Pb(Mg1/3Nb2/3)O3-PbTiO3 Ferroelectric Nano-Films Grown on Si Substrates

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2392 ◽  
Author(s):  
Changlong Cai ◽  
Deqiang Zhang ◽  
Weiguo Liu ◽  
Jun Wang ◽  
Shun Zhou ◽  
...  
Keyword(s):  
Thin Films ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Pyroelectric Coefficient ◽  
X Ray Diffraction ◽  
Si Substrates ◽  
A Value ◽  
Giant Dielectric ◽  
Current Densities ◽  
Pyroelectric Response

The [001]-oriented Pr3+ doped Pb(Mg1/3Nb2/3)O3-0.30PbTiO3 (Pr-PMN-PT) thin films with a composition near the morphotropic phase boundary (MPB) were synthesized by a sol–gel method. The crystal structure was characterized using X-ray diffraction. It was found that a single perovskite phase was achieved in Pr-PMN-PT thin films annealed at 650 °C for 3 min. The dielectric constant (εr) value was 2400 in 2.5% Pr-PMN-PT thin films at room temperature, 110% higher than that of pure PMN-PT samples. Through 2.5% Pr3+ doping, remanent polarization (Pr) and coercive field (Ec) values increased from 11.5 μC/cm2 and 35 kV/cm to 17.3 μC/cm2 and 63.5 kV/cm, respectively, in PMN-PT thin films. The leakage current densities of pure and 2.5% Pr-PMN-PT thin films were on the order of 1.24 × 10−4 A/cm2 and 5.8 × 10−5 A/cm2, respectively, at 100 kV/cm. A high pyroelectric coefficient (py) with a value of 167 μC/m2K was obtained in 2.5% Pr-PMN-PT thin films on Si substrate, which makes this material suitable for application in infrared detectors.

Structure and Optical Properties of Nanocrystalline Yttria Doped Ceria Thin Films

1998 ◽  
Vol 12 (15) ◽  
pp. 1573-1583 ◽  
Author(s):  
A. Hartridge ◽  
M. Ghanashyam Krishna ◽  
A. K. Bhattacharya
Keyword(s):  
Thin Films ◽  
Optical Band Gap ◽  
Dopant Concentration ◽  
Sol Gel ◽  
Doped Ceria ◽  
Optical Losses ◽  
Glass Substrates ◽  
A Value ◽  
Free Region ◽  
Yttria Doped Ceria

Thin films of Ce 1-x Y x O 2-y where x ranges from 0 to 0.5 have been coated onto glass substrates using an inorganic sol–gel approach at low temperature. The lattice parameters from powder diffraction measurements were calculated and shown to be very close to those previously reported. Crystallite size measurements indicated that the films were nanocrystalline, the size decreasing as a function of dopant concentration. The films are transparent in the region 500 to 1500 nm with very low optical losses. The film refractive index is dependent on the dopant concentration and peaks at an yttria concentration of x=0.25 after treatment at 450° C , with a value of 1.79, which on increasing the yttria concentration to x=0.50 decreases to 1.65 in the dispersion free region. The optical band gap is also dependent on the dopant concentration and is in the range 3.2 to 3.0 eV.

Effects of Sm and Mn Co-Doping on Structural and Optical Properties of BiFeO3 Thin Films Prepared by Sol-Gel Technique

2015 ◽  
Vol 815 ◽  
pp. 149-153 ◽  
Author(s):  
Wen Liang Zhou ◽  
Hong Mei Deng ◽  
Jun He ◽  
Jian Liu ◽  
Hui Yi Cao ◽  
...  
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
Co Doping ◽  
Average Grain Size ◽  
Gel Technique ◽  
Diffraction Patterns ◽  
Quartz Substrates ◽  
Rhombohedral Perovskite Structure

(Bi1-xSmx)(Fe0.95Mn0.05)O3(x=0.00, 0.03 and 0.06) thin films were deposited on the quartz substrates by sol-gel technique. The results of X-ray diffraction patterns indicated all thin films had rhombohedral perovskite structure. Moreover, the Sm and Mn co-doping at A-and B-site of BiFeO3resulted in the structural distortion. Scanning electron microscope measurements exhibited that the uniform surface morphology could be obtained by co-doping and the average grain size of the films decreased with increasing Sm content. Furthermore, the fundamental absorption edges ofxBSFMO films showed a blue shift with the increase of Sm content which can be observed in transmittance spectra. The optical band gap of the thin films forx= 0.00, 0.03 and 0.06 can be expressed by (0.84x+2.62) eV, which is due to the Burstein-Moss effect.

Lower crystallization temperature of sol-gel PbTiO3 on Ti/Pt-coated substrates

1999 ◽  
Vol 14 (6) ◽  
pp. 2369-2372 ◽  
Author(s):  
R. E. Avila ◽  
T. P. Velilla ◽  
P. J. Retuert
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Refractive Index ◽  
Sintering Temperature ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Range Analysis ◽  
X Ray

PbTiO3 (PT) thin films have been deposited by sol-gel on Pt/Si, SiO2/Si, Pt/Ti/SiO2/Si, and Ti/Pt/Ti/SiO2/Si and annealed for 45 min in the 400–670 °C range. Analysis by x-ray diffraction (XRD) and spectroscopic ellipsometry shows that the Ti overlayer promotes early crystallization in the tetragonal perovskite phase, reducing the presence of a second phase, tentatively identified as pyrochlore, starting by 450 %C. The refractive index and extinction coefficient (n, k) of the PT film increase rapidly with the sintering temperature in the range of 450–570 °C and saturate by 570 °C to values of n varying from 2.4 to 2.9, and k from 0.03 to 0.3, over the 1.65–2.95 eV range. Most of the increase of n is related to thin film densification.

Sol-gel growth of Ni doped CdS on glass substrates: effect of spin coating speed and dopant concentration

2020 ◽  
Vol 10 ◽  
Author(s):  
Atefeh Nazari Setayesh ◽  
Hassan Sedghi
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spin Coating ◽  
Optical Band Gap ◽  
Dopant Concentration ◽  
Rotation Speed ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Glass Substrates

Background: In this work, CdS thin films were synthesized by sol-gel method (spin coating technique) on glass substrates to investigate the optical behavior of the film. Methods: Different substrate spin coating speeds of 2400, 3000, 3600 rpm and different Ni dopant concentrations of 0 wt.%, 2.5 wt.%, 5 wt.%) were investigated. The optical properties of thin films such as refraction index, extinction coefficient, dielectric constant and optical band gap energy of the layers were discussed using spectroscopic ellipsometry method in the wavelength range of 300 to 900 nm. Results: It can be deduced that substrate rotation speed and dopant concentration has influenced the optical properties of thin films. By decreasing rotation speed of the substrate which results in films with more thicknesses, more optical interferences were appeared in the results. Conclusion: The samples doped with Ni comparing to pure ones have had more optical band gap energy.

ITO Thin Films on Silicon Buffer by Sol Gel Method

2006 ◽  
Vol 514-516 ◽  
pp. 1155-1160 ◽  
Author(s):  
Talaat Moussa Hammad
Keyword(s):  
Thin Films ◽  
Indium Tin Oxide ◽  
Optical Transmission ◽  
Sol Gel ◽  
Precursor Solution ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ito Thin Films ◽  
Uv Visible

Sol gel indium tin oxide thin films (In: Sn = 90:10) were prepared by the sol-gel dipcoating process on silicon buffer substrate. The precursor solution was prepared by mixing SnCl2.2H2O and InCl3 dissolved in ethanol and acetic acid. The crystalline structure and grain orientation of ITO films were determined by X-ray diffraction. The surface morphology of the films was characterized by scanning electron microscope (SEM). Optical transmission and reflectance spectra of the films were analyzed by using a UV-visible spectrophotometer. The transport properties of majority charge carriers for these films were studied by Hall measurement. ITO thin film with electrical resistivity of 7.6 ×10-3 3.cm, Hall mobility of approximately 2 cm2(Vs)-1 and free carrier concentration of approximately 4.2 ×1020 cm-3 are obtained for films 100 nm thick films. The I-V curve measurement showed typical I-V characteristic behavior of sol gel ITO thin films.

Characterization of SrBi2Nb2O9 Thin Films Prepared by Sol Gel Technique

1996 ◽  
Vol 459 ◽  
Author(s):  
E. Ching-Prado ◽  
W. Pérez ◽  
A. Reynés-Figueroa ◽  
R. S. Katiyar ◽  
D. Ravichandran ◽  
...  
Keyword(s):  
Thin Films ◽  
Raman Band ◽  
Sol Gel ◽  
Orthorhombic Symmetry ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Gel Technique ◽  
High Degree ◽  
First Time

ABSTRACTThin films of SrBi2Nb2O9 (SBN) with thicknesses of 0.1, 0.2, and 0.4 μ were grown by Sol-gel technique on silicon, and annealed at 650°C. The SBN films were investigated by Raman scatering for the first time. Raman spectra in some of the samples present bands around 60, 167, 196, 222, 302, 451, 560, 771, 837, and 863 cm−1, which correspond to the SBN formation. The study indicates that the films are inhomogeneous, and only in samples with thicknesses 0.4 μ the SBN material was found in some places. The prominent Raman band around 870 cm−1, which is the A1g mode of the orthorhombic symmetry, is assigned to the symmetric stretching of the NbO6 octahedrals. The frequency of this band is found to shift in different places in the same sample, as well as from sample to sample. The frequency shifts and the width of the Raman bands are discussed in term of ions in non-equilibrium positions. FT-IR spectra reveal a sharp peak at 1260 cm−1, and two broad bands around 995 and 772 cm−1. The bandwidths of the latter two bands are believed to be associated with the presence of a high degree of defects in the films. The experimental results of the SBN films are compared with those obtained in SBT (T=Ta) films. X-ray diffraction and SEM techniques are also used for the structural characterization.

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