Performance of the Yb/n-CdSe/C Tunneling Barriers

2018 ◽  
Vol 13 (10) ◽  
pp. 1493-1498
Author(s):  
A. F. Qasrawi
Keyword(s):  
Thin Films ◽  
Frequency Domain ◽  
Physical Vapor Deposition ◽  
Optoelectronic Device ◽  
Depletion Region ◽  
X Ray ◽  
Tunneling Mechanism ◽  
Vapor Deposition Technique ◽  
And Performance ◽  
Physical Vapor Deposition Technique

In this article, the design and performance of the CdSe which are deposited onto thin films of Yb metal is reported and discussed. The thin films of CdSe which are deposited by the physical vapor deposition technique are observed to exhibit slightly deformed hexagonal polycrystalline nature with excess amount of Cd as confirmed by the X-ray, energy dispersive X-ray spectroscopy and scanning electron microscopy techniques. The n-type CdSe is also found to form a Schottky barrier of tunneling type when sandwiched between Yb and carbon. The quantum mechanical tunneling mechanism in this device which was tested and modeled in the frequency domain of 10–150 MHz is found to exhibit average intersite separations of ∼5 nm. The tunneling device exhibited a widening in the depletion region associated with significantly large capacitance tunability in the studied frequency domain. On the other hand, as an optoelectronic device, the Yb/n-CdSe/C Schottky diode exhibited a responsivity of ∼0.10 A/W, photosensitivity of 6.5 × 104 and external quantum efficiency of 54% when biased with 1.0 V and exposed to laser light of wavelength of 406 nm.

Preparation of Pb(Zr0.54Ti0.46)O3 Thin Films on (100)Si Using Textured YBa2Cu3O7−δ and Yttria-Stabilized Zirconia Buffer Layers by Laser Physical Vapor Deposition Technique

1992 ◽  
Vol 285 ◽  
Author(s):  
P. Tiwari ◽  
T. Zheleva ◽  
A. Morimoto ◽  
V.N. Shukla ◽  
J. Narayan
Keyword(s):  
Thin Films ◽  
Physical Vapor Deposition ◽  
Ferroelectric Properties ◽  
Processing Parameters ◽  
Yttria Stabilized Zirconia ◽  
Buffer Layers ◽  
Stabilized Zirconia ◽  
Vapor Deposition Technique ◽  
Pzt Films ◽  
Physical Vapor Deposition Technique

ABSTRACTWe have fabricated high-quality <001> textured Pb(Zr0.54Ti0.46)O3 (PZT) thin films on (001)Si with interposing <001> textured YBa2Cu3O7−δ (YBCO) and yttria-stabilized zirconia (YSZ) buffer layers using pulsed laser deposition (KrF excimer laser, λ=248 nm, τ=20 nanoseconds). The YBCO layer provides a seed for PZT growth and can also act as an electrode for the PZT films, whereas YSZ provides a diffusion barrier as well as a seed for the growth of YBCO films on (001)Si. These heterostructures were characterized using X-ray diffraction, high-resolution transmission electron microscopy and Rutherford backscattering techniques. The YSZ films were deposited in oxygen ambient (∼9X10−4 torr) at 775°C on (001)Si substrate having <001>YSZ// <001>Si texture. The YBCO thin films were deposited in-situ in oxygen ambient (200 mtorr) at 650°C. Temperature and oxygen ambient for the PZT deposition were optimized to be 530°C and 0.4–0.6 torr, respectively. The laser fluence to deposit this multistructure was 2.5–5.0 J/cm2. The <001> textured perovskite PZT films showed a dielectric constant of 800–1000, a saturation polarization of 37.81 μC/cm2, remnant polarization of 24.38 μC/cm2 and a coersive field of 125 kV/cm. The effects of processing parameters on microstructure and ferroelectric properties of PZT films and device implications of these structures are discussed.

Low Temperature Laser Physical Vapor Deposition of Multilayered Thin Films

1989 ◽  
Vol 158 ◽  
Author(s):  
N. Biunno ◽  
J. Krishnaswamy ◽  
S. Sharan ◽  
L. Ganapathi ◽  
J. Narayan
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Layer By Layer ◽  
Deposition Technique ◽  
Target Holder ◽  
Multi Stage ◽  
Vapor Deposition Technique ◽  
Physical Vapor Deposition Technique

ABSTRACTWe have investigated the formation of various multilayer thin films by the laser physical vapor deposition technique. A multi stage target holder was constructed to perform all process steps in-situ; target/substrate cleaning, deposition, and annealing. The laser physical vapor deposition technique offers many advantages over conventional physical vapor techniques, such as, lower substrate temperature, microstructural control, and very low contamination levels. Film thickness can be controlled from near atomic to micron dimensions. A layer-by-layer (two dimensional) growth can be achieved, resulting in nonequilibrium structures. The films were analyzed using cross-section and high resolution transmission electron microscopy (TEM). The significant reduction in substrate temperature for the formation of high quality multilayer and epitaxial films opens up many new areas of applications requiring reduced thermal-budget processing.

scholarly journals Effect of Thickness on Structural and Optical Properties of Tetra-tert- butyl-2, 3-naphthalocyanine Thin Films

2011 ◽  
Vol 8 (4) ◽  
pp. 1686-1695 ◽  
Author(s):  
I. Dhanya ◽  
C S Menon
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Physical Vapor Deposition ◽  
Band Gap Energy ◽  
Dielectric Constants ◽  
Localized States ◽  
Optical Parameters ◽  
Tert Butyl ◽  
Vapor Deposition Technique ◽  
Physical Vapor Deposition Technique

Amorphous tetra-tert-butyl-2, 3-naphthalocyanine thin films have been deposited using physical vapor deposition technique under a varied thickness by adjusting the coating time. By analyzing the x-ray diffraction, the structure of as deposited films is found to be non-crystalline. Different optical properties of these thin films have been investigated by means of optical absorption and reflection spectra. Various optical constants like band gap energy, Egthe width of band tails of localized states into the gap, EUand steepness parameter, β gets calculated and the variation of different optical parameters like refractive index, extinction coefficient, dielectric constants, optical conductivity and surface and volume energy losses with photon energy are estimated.

scholarly journals Physical Vapor Deposited Silver (AG) Based Metal-Dielectric Nanocomposites for Advanced Thin-Film and Coating Applications

2021 ◽  
Author(s):  
Mohammad Nur-E-Alam ◽  
Mohammad Khairul Basher ◽  
Mikhail Vasiliev ◽  
Narottam Das
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Future Application ◽  
Thin Film Coatings ◽  
Environment And Health ◽  
Vapor Deposition Technique ◽  
Nanocomposite Thin Films ◽  
Physical Vapor Deposition Technique

Metallic thin-film materials and nanoparticles (mainly Silver (Ag)-based) are recently being used in many nano-technological applications including sensors, reflective heat-mirror coatings, and antibacterial coatings as well. The physical vapor deposition technique attracts significant attention for Ag-based nanocomposites with tailoring the structural and optical properties of metallic thin films thus allowing further improvements and application possibilities in various existing fields namely electronics, catalysis, magnetics, optics in alongside the environment and health and new emergent fields in, particularly thin-film coatings. This study highlights the preparation, characterization, properties, and possible future application directions of several types of Silver (Ag)-based nanocomposite thin films prepared by using physical vapor deposition techniques.

scholarly journals A Combined Experimental and Tddft-dft Investigation of Structural and Optical Properties of Novel Pyrazole-1, 2, 3-triazole Hybrids as Optoelectronic Devices

2021 ◽  
Author(s):  
Islam H. El Azab ◽  
A. Ibrahim ◽  
M. Abdel El-Moneim ◽  
M. Sh. Zoromba ◽  
Mohamed Helmy Abdel-Aziz ◽  
...  
Keyword(s):  
Thin Film ◽  
Optical Properties ◽  
Electronic Transition ◽  
Physical Vapor Deposition ◽  
Defect Formation ◽  
Energy Gap ◽  
Promising Result ◽  
Optoelectronic Device ◽  
Vapor Deposition Technique ◽  
Physical Vapor Deposition Technique

Abstract A conjugated semiconductor thin film of 1-((3-(3-(3,5-diphenyl-4,5-dihydro-1H-pyrazol-1-yl)-5-methyl-1H-1,2,4-triazol-1-yl)-1-phenyl-1H-pyrazol-4-yl)methyl)-4-phenyl-1H-1,2,3-triazole [4ph-TAzole]TF was synthesized. The characterization of the obtained [4ph-TAzole]TF powder is carried out using different techniques includes FTIR, UV-Vis, 1HNMR, XRD, and mass spectra. The fabricated [4ph-TAzole]TF thin film with a thickness of 150 ± 3 nm is manufactured by physical vapor deposition technique (PVD) at a low deposition rate with basic pressure of the chamber was 5×10− 5 mbar. Using DFT-TDDFT simulation, the structure measurements can determine the energy gap and optical properties. The obtained DFT-TDDFT data provide good proof for the electronic transition in zero-dimensional [4ph-TAzole]TF as a single crystal molecule. This study provides valuable information on the nature and sources of defect formation and electronic transition in conductor organic derivate of triazole which open the way for the application as an optoelectronic device. Application Davis’s and Shilliday’s equation on [4ph-TAzole]TF mentioned that the \({\text{E}}_{\text{g}}^{\text{D}\text{i}\text{r}}\)and \({\text{E}}_{\text{g}}^{\text{I}\text{n}\text{d}}\)transitions can be computed by plotting \(({{\alpha }\text{h}{\nu })}^{2}\) and \(({{\alpha }\text{h}{\nu })}^{0.5}\) versus \(\text{h}{\nu }\) nearby the value of fundamental band edge (\(({{\alpha }\text{h}{\nu })}^{2}\) and \(({{\alpha }\text{h}{\nu })}^{0.5}\) parts) in the computed Abs. (λ) curves to zero absorption value, respectively. The direct and indirect energies were 2.651eV and 3.01 eV for [4ph-TAzole]TF, respectively. The obtained thin film presents a promising result to be a good candidate for organic derivate of triazole solar cell applications.

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