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 Features of optical properties of high stable CdTe photovoltaic absorber layer

2020 ◽  
Vol 21 (2) ◽  
pp. 243-253
Author(s):  
R.S. Yavorskyi
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Cadmium Telluride ◽  
Physical Vapor Deposition ◽  
Vacuum Chamber ◽  
Wavelength Region ◽  
Thermal Evaporation Method ◽  
Vapor Deposition Technique ◽  
Transmission Measurements ◽  
Physical Vapor Deposition Technique

In this paper, the technology of obtaining and effect of annealing on the morphology and optical properties of cadmium telluride thin films has been investigated. The effect of vacuum chamber modes on the growth of thin films has been studied. For obtained cadmium telluride thin films were used a modified thermal evaporation method deposited by Physical Vapor Deposition technique on a glass substrate with different thicknesses. The transmission measurements were carried with UV-ViS-NIR Spectrophotometer in the wavelength range 180-3300 nm, to analyze the optical properties as a function of wavelength. The optical band gap values were 1.49 eV for as-grown films and 1.46 eV after annealing. The refractive indexes of the samples were defined in the range of 2.6 – 2.8 for as-grown films and the indexes have increased after annealing depending on the wavelength region and film thickness. After annealing, the coalescence mode of growth is observed.

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.

INVESTIGATING ANNEALING EFFECT ON OPTICAL PROPERTIES OF Cd0.8Zn0.2S THIN FILMS

2014 ◽  
Vol 21 (05) ◽  
pp. 1450073 ◽  
Author(s):  
SOMAYEH AZIZI ◽  
HAMID REZAGHOLIPOUR DIZAJI ◽  
MOHAMMAD HOSSEIN EHSANI ◽  
SEYED FEYZOLAH GHAVAMI MIRMAHALLE
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Hexagonal Wurtzite Structure ◽  
Band Gap Energy ◽  
Annealing Effect ◽  
Thin Layers ◽  
Optical Parameters ◽  
Thermal Evaporation Method ◽  
X Ray ◽  
Glass Substrates

Cd 0.8 Zn 0.2 S thin films deposited on glass substrates by thermal evaporation method were annealed at different temperatures for the first time in order to investigate annealing effect on optical properties. The compositional, structural of nanoparticles precursor synthesized using microwave irradiation method and optical properties of the films were studied using energy dispersive X-ray (EDX), X-ray diffraction, transmission electron microscopy (TEM), and UV-visible spectrophotometer techniques. The annealed films were found to have hexagonal Wurtzite structure with strong preferential orientation along the (002) diffraction peak. Important optical parameters such as extinction coefficient and refractive index revealed the effect of heat treatment on the deposited thin layers. A reduction in the band gap energy from 2.41 eV to 2.29 eV was observed for the annealed samples.

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.

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 Optical properties of CdS/CdTe heterojunction prepared by physical vapor deposition technique

2019 ◽  
Vol 19 (3) ◽  
pp. 209-216
Author(s):  
L.` Nykyruy ◽  
O. Yaremiichuk ◽  
Z. Zapukhlyak ◽  
R. Yavorskyi ◽  
P. Potera ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Thin Layer ◽  
Physical Vapor Deposition ◽  
Cadmium Sulphide ◽  
Thermal Evaporation Method ◽  
Glass Substrates ◽  
Vapor Deposition Technique ◽  
Cdte Thin Films ◽  
Swanepoel Method

The paper presents the study of the optical properties of a thin layer of Cadmium Sulphide deposited on Cadmium Telluride films. CdTe thin films were obtained by vapor phase condensation method using different technological factors, in particular, different thickness (different time of deposition τ) on glass substrates. After deposition the optical properties were analysed by Swanepoel method, using transmission spectra. The upper thin layer of CdS was deposited by thermal evaporation method on CdTe thin films. The change in optical properties of CdS/CdTe heterojunction in comparison with CdTe thin films was investigated. Using a Swanepoel method were calculated the main optical constants, such as refractive index, absorption coefficient and optical conductivity. By this method the thickness of the thin film was determined and compared with the experimental values obtained by the profilometer.

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