scholarly journals Electro-Optical Properties of Sputtered Calcium Lead Titanate Thin Films for Pyroelectric Detection

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1073
Author(s):  
Elham Mafi ◽  
Nicholas Calvano ◽  
Jessica Patel ◽  
Md. Sherajul Islam ◽  
Md. Sakib Hasan Khan ◽  
...  
Keyword(s):  
Thin Films ◽  
Lead Titanate ◽  
Density Functional ◽  
Pyroelectric Coefficient ◽  
X Ray Diffraction ◽  
Radio Frequency Sputtering ◽  
Pyroelectric Current ◽  
Pyroelectric Detectors ◽  
Higher Temperature ◽  
Calcium Lead

We report the deposition and characterization of calcium lead titanate (PCT) thin films for pyroelectric detectors. PCT films of thicknesses ranging from ~250 to 400 nm were deposited on both silicon and Si/SiN/Ti/Au substrates at 13 mTorr pressure by 200W radio frequency sputtering in an Ar + O2 environment. Substrates were kept at variable temperatures during the deposition. The PCT films were annealed at various temperatures in an O2 environment for 15 min. X-ray diffraction results confirm the polycrystalline nature of these films. Energy dispersive spectroscopy function of scanning electron microscope showed that the films are stoichiometric (Ca0.43Pb0.57) TiO3 (Ca/Ti = 0.5, Pb/Ti = 0.66). Temperature dependence of capacitance, pyroelectric current, and pyroelectric coefficient was investigated for different PCT films. Our results show that films deposited at 550 °C and 600 °C demonstrate better quality and larger values of the pyroelectric coefficient. On the other hand, the capacitance fabricated on the PCT films at 550 °C showed the highest value of pyroelectric current and pyroelectric coefficient which were 14 pA and at 30 °C was ~2 µC/m2K respectively at a higher temperature. In addition, we used density functional theory to determine the atomic and band structure, real and imaginary parts of dielectric constant and refractive index, and absorption and reflection constants with energy.

Al1-x ScxN Thin Film Structures for Pyroelectric Sensing Applications

MRS Advances ◽  
2016 ◽  
Vol 1 (39) ◽  
pp. 2711-2716 ◽  
Author(s):  
V. Vasilyev ◽  
J. Cetnar ◽  
B. Claflin ◽  
G. Grzybowski ◽  
K. Leedy ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Pyroelectric Coefficient ◽  
X Ray Diffraction ◽  
Ir Detectors ◽  
Pyroelectric Properties ◽  
X Ray ◽  
Sensing Applications ◽  
Pyroelectric Material ◽  
Deposited Films

ABSTRACTAlN thin film structures have many useful and practical piezoelectric and pyroelectric properties. The potential enhancement of the AlN piezo- and pyroelectric constants allows it to compete with more commonly used materials. For example, combination of AlN with ScN leads to new structural, electronic, and mechanical characteristics, which have been reported to substantially enhance the piezoelectric coefficients in solid-solution AlN-ScN compounds, compared to a pure AlN-phase material.In our work, we demonstrate that an analogous alloying approach results in considerable enhancement of the pyroelectric properties of AlN - ScN composites. Thin films of ScN, AlN and Al1-x ScxN (x = 0 – 1.0) were deposited on silicon (004) substrates using dual reactive sputtering in Ar/N2 atmosphere from Sc and Al targets. The deposited films were studied and compared using x-ray diffraction, XPS, SEM, and pyroelectric characterization. An up to 25% enhancement was observed in the pyroelectric coefficient (Pc = 0.9 µC /m2K) for Sc1-xAlxN thin films structures in comparison to pure AlN thin films (Pc = 0.71 µC/m2K). The obtained results suggest that Al1-x ScxN films could be a promising novel pyroelectric material and might be suitable for use in uncooled IR detectors.

Structural, Dielectric and Pyroelectric properties of Lanthanum modified Lead Titanate Thin Films

2004 ◽  
Vol 811 ◽  
Author(s):  
Sonalee Chopra ◽  
Seema Sharma ◽  
T.C. Goel ◽  
R.G. Mendiratta
Keyword(s):  
Thin Films ◽  
Lead Titanate ◽  
Mechanical Stability ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Microstructural Analysis ◽  
Pyroelectric Coefficient ◽  
Structural Investigations ◽  
Glass Substrates

ABSTRACTFerroelectric lead lanthanum titanate (Pb1−xLaxTi1−x/4O3) (PLTx) thin films (x=0.04,0.08 and 0.12) have been prepared by sol-gel spin coating process on ITO coated 7059 Corning glass substrates. Investigations have been made on the crystal structure, surface morphology, dielectric and ferroelectric properties of the thin films. For a better understanding of the crystallization mechanism, the structural investigations were carried out at various annealing temperatures (350°C, 450°C, 550°C and 650°C). Characterization of these films by X-ray diffraction shows that the films annealed at 650°C exhibit tetragonal structure with perovskite phase. Replacement of lanthanum in lead titanate results in reduction of tetragonal ratio (c/a), resulting in better mechanical stability. Microstructural analysis of the films are carried out by taking the Atomic Force Microscope (AFM) pictures. AFM images are characterized by slight surface roughness with a uniform crack free, densely packed structure. Dielectric, pyroelectric and ferroelectric studies carried out on these films have been reported. Dielectric constant and pyroelectric coefficient increase while Curie temperature decreases with increase in La content. The pyroelectric figures of merit of the films have also been calculated which suggest that 8% lanthanum is best suited material for pyroelectric detectors owing to its high pyroelectric coefficient (∼ 29nC/cm2 K), high voltage responsivity (∼420Vcm2/J), high detectivity (∼1.04×10−5Pa−1/2) and low variation of pyrocoefficient with temperature.

Structure and Characterization of Sputtered Thin Films Based on Lead Titanate.

1991 ◽  
Vol 230 ◽  
Author(s):  
A. Pignolet ◽  
P. E. Schmid ◽  
L. Wang ◽  
F. Lévy
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Lead Titanate ◽  
Rf Magnetron Sputtering ◽  
Lead Zirconate ◽  
Pyroelectric Coefficient ◽  
Amorphous Films ◽  
Substrate Heating ◽  
Ferroelectric Hysteresis

AbstractPure and doped lead-titanate (PT) and lead-zirconate-titanate (PZT) thin films have been deposited on platinum-coated silicon by rf-magnetron sputtering from pressed powder targets. The films have been deposited without substrate heating. The amorphous films were then annealed in an oxygen flow. The structure of the films is tetragonal or rhombohedral depending on composition. The electrical resistivity, dielectric permittivity, ferroelectric hysteresis and pyroelectric coefficient are reported.

Growth of heteroepitaxial GaSb thin films on Si(100) substrates

2004 ◽  
Vol 19 (8) ◽  
pp. 2315-2321 ◽  
Author(s):  
Thang Nguyen ◽  
Walter Varhue ◽  
Edward Adams ◽  
Mark Lavoie ◽  
Stephen Mongeon
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Lattice Mismatch ◽  
Stacking Faults ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Radio Frequency Sputtering ◽  
Atomic Force ◽  
Transmission Electron

The heteroepitaxial growth of GaSb thin films on Si(100) and GaAs(100) substrates is presented. The growth technique involves the use of atomic Ga and Sb species, which are provided by thermal effusion and radio frequency sputtering, respectively. The crystalline quality of the heteroepitaxial GaSb film on the Si substrate is high despite the larger lattice mismatch. Epitaxial quality is determined by high-resolution x-ray diffraction and Rutherford backscatter spectrometry channeling. Atomic-force microscopy is used to monitor the evolution of surface morphology with increasing film thickness. Transmission electron microscopy shows the formation of stacking faults at the Si/GaSb interface and their eventual annihilation with increasing GaSb film thickness. Annihilation of stacking faults occurs when two next-neighbor mounds meet during the overgrowth of a common adjacent mound.

Sol-gel-derived lead and calcium lead titanate pyroelectric detectors on silicon MEMS structures

1996 ◽  
Author(s):  
James G. Ho ◽  
Phyllis R. Nelson ◽  
Felice H. Lin ◽  
David T. Chang ◽  
William J. Kaiser ◽  
...  
Keyword(s):  
Lead Titanate ◽  
Sol Gel ◽  
Pyroelectric Detectors ◽  
Calcium Lead

Characterizations of Nitrogen Doped Cupric Oxide Thin Films Deposited on Different Substrates for Solar Cell Applications

2014 ◽  
Vol 925 ◽  
pp. 469-473
Author(s):  
Poh Kok Ooi ◽  
Mohd Anas Ahmad ◽  
Sha Shiong Ng ◽  
Mat Johar Abdullah
Keyword(s):  
Thin Films ◽  
Cupric Oxide ◽  
Schottky Contact ◽  
Optical And Electrical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nitrogen Doped ◽  
Radio Frequency Sputtering ◽  
Indirect Band Gap ◽  
Sputtering System

In this work, structural, optical and electrical properties of nitrogen doped (N-doped) cupric oxide (CuO) thin films deposited on <100> orientated n-type silicon, glass and polyethylene terephthalate substrates using reactive radio frequency sputtering system were investigated. X-ray diffraction results revealed that all films exhibited monoclinic CuO(-111) and have only slightly different structural properties for various substrates. Field effect scanning electron microscopy shown N-doped CuO on Si and glass are denser than on PET substrates and all have nanotriangle-like structure morphologies. The N-doped CuO thin films have an indirect band gap of around 1.30 eV. The resistively, carrier concentration and hall mobility of the N-doped CuO thin film on glass were 1.05 kΩ.cm, 6.70 x 1014 cm-3 and 8.86 cm2/V-s respectively. Furthermore, palladium formed ohmic contact characteristics for N-doped CuO on glass and PET but exhibited schottky contact characteristics for N-doped CuO on Si.

Phase development in Si modified sol-gel-derived lead titanate

1993 ◽  
Vol 8 (7) ◽  
pp. 1712-1720 ◽  
Author(s):  
John S. Wright ◽  
Lorraine Falter Francis
Keyword(s):  
Lead Titanate ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Phase Development ◽  
Higher Temperature ◽  
Si Content ◽  
Si Addition

Sol-gel methods were used to prepare chemically modified lead titanate (PT) powders. A PT alkoxide solution was synthesized and doped with Si (2–12 mole%) or with equimolar amounts (2–12 mole%) of Si and Pb through the addition of Si and Pb–Si alkoxide solutions, respectively. PT alkoxide solutions were also prepared with excess Pb and Ti (7 and 10 mole%). Gels were prepared through controlled additions of water. Crystalline phase development of gel-derived powders with heat treatment (400–700 °C) was studied using x-ray diffraction (XRD) and differential thermal analysis (DTA). While PT powders without added Si crystallized directly into a perovskite phase, Si modified materials crystallized first into a pyrochlore phase and at a higher temperature transformed into perovskite. The pyrochlore lattice parameter and the temperature for the transformation to perovskite increased with Si content. In all cases, the crystal structure of the final perovskite phase was not affected by the Si addition. The effect of Si on phase development and mechanisms of transformation is discussed.

scholarly journals Structural phase evolution of strontium-doped lead titanate thin films prepared by the soft chemical technique

2003 ◽  
Vol 18 (3) ◽  
pp. 659-663 ◽  
Author(s):  
F. M. Pontes ◽  
S. H. Leal ◽  
P. S. Pizani ◽  
M. R. M. C. Santos ◽  
E. R. Leite ◽  
...  
Keyword(s):  
Thin Films ◽  
Lead Titanate ◽  
Structural Phase ◽  
Phase Evolution ◽  
Gradual Change ◽  
X Ray Diffraction ◽  
Strontium Concentration ◽  
Si Substrates ◽  
Specular Reflectance ◽  
Chemical Technique

Strontium-modified lead titanate thin films with composition Pb1−xSrxTiO3 were grown on Pt/Ti/SiO2/Si substrates using the polymeric precursor method. The structural phase evolution as a function of the Sr contents was studied using micro-Raman scattering, specular reflectance infrared Fourier transform spectroscopy, and x-ray diffraction. The results showed a gradual change from tetragonal to cubic structure, the transition occurring at about x = 0.58. The infrared reflectance spectra showed that the frequency of several peaks decreases as the strontium concentration increases. These features are correlated with a decrease in the tetragonal distortion of the TiO6 octahedra as the strontium concentration increases.

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