Optical Properties of Strained Polycrystalline CuInS2 Layers

2007 ◽  
Vol 1012 ◽  
Author(s):  
Jens Eberhardt ◽  
Heinrich Metzner ◽  
Rüdiger Goldhahn ◽  
Florian Hudert ◽  
Kristian Schulz ◽  
...  
Keyword(s):  
Optical Properties ◽  
Buffer Layer ◽  
Tensile Strain ◽  
Transition Energy ◽  
Molecular Beams ◽  
Oscillator Strengths ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Yield Information

AbstractUsing molecular beams, polycrystalline thin CuInS2 (CIS) films of different thicknesses were grown on Si substrates covered with a sputtered Mo-buffer layer. Systematic photoluminescence and photoreflectance measurements were performed to investigate the influence of strain - introduced during growth - on the optical properties. The transition energy of the free A-exciton (FXA) decreases with increasing tensile strain caused by (i) increasing thickness of the Mo buffer layer and (ii) decreasing thickness of the CIS layer. Furthermore, the energetic splittings between FXA, FXB, and FXC increase with increasing tensile strain. When combined with X-ray diffraction data, the oscillator strengths of the excitonic transitions yield information on the strain distribution within the films.

Epitaxial Relationships and Electrical Properties of SrTiO3 Films on Various Thin -Fluoride/Si Structures

1994 ◽  
Vol 341 ◽  
Author(s):  
B. K. Moon ◽  
H. Ishiwara
Keyword(s):  
Buffer Layer ◽  
Buffer Layers ◽  
Breakdown Field ◽  
X Ray Diffraction ◽  
Dielectric Characteristics ◽  
X Ray ◽  
Si Substrates ◽  
Initial Stage ◽  
Growth Method ◽  
Step Growth

AbstractCrystalline strontium titanate (SrTiO3:STO) films were grown on Si(111) and Si(100) substrates using thin SrF2 and CaF2 buffer layers by two-step growth method. In all cases, fluoride buffer layers were effective in growing STO films on Si substrates, which is probably due to that fluoride buffer layers have excellent crystallinity and they can prevent formation of amorphous SiO2 layers on Si substrates at the initial stage of the STO deposition. It was found from X-ray diffraction and pole-figure measurements that (110)-oriented STO crystallites with three different positions to the substrate were grown on Si(111) substrates for both SrF2 and CaF2 buffer layers. In constrast, (100)-oriented STO films with 12-fold symmetry were grown on a SrF2/Si(100), and mixed (110)- and (100)-oriented STO crystallites were grown on a CaF2/Si(100) structure. It was concluded from these results that better crystallinity of STO films can be obtained on the SrF2 buffer layer in case of Si(111) and on the CaF2 buffer layer in case of Si(100). It was also found from I-V and C-V analyses that the STO films have good insulating and dielectric characteristics. For a SrTiO3 film on SrF2/Si(111) structure, the best values of breakdown field (at l.μA/cm2), resistivity (at IMV/cm) and dielectric constant were 2.3MV/cm, 8.2 × 1012 Ωcm and 72, respectively.

Twinning in epilayers of CdTe on Si: Influence of ZnTe buffer layer and substrate misorientation

1995 ◽  
Vol 399 ◽  
Author(s):  
A. Gray ◽  
N.K. Dhar ◽  
W. Clark ◽  
P. Charlton ◽  
J.H. Dinan ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Buffer Layer ◽  
Molecular Beam ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates

ABSTRACTX-ray diffraction spectra of CdTe epilayers grown with and without ZnTe buffer layers on <211> Si substrates by molecular beam epitaxy consist of 422 and 331 reflections. We interpret these as evidence for the existence of twins within the volume of a <211> oriented epilayer and show that twin volume is dependent on the ZnTe buffer layer and substrate misorientation.

Optical Properties of Thermally Oxidized Silicon

1994 ◽  
Vol 342 ◽  
Author(s):  
O.L. Russo ◽  
N.M. Ravindra ◽  
J.M. Grow ◽  
K.A. Dumas
Keyword(s):  
Optical Properties ◽  
Complex Refractive Index ◽  
Compressive Strain ◽  
Oxide Thickness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Infra Red ◽  
Si Model ◽  
Model Strain

ABSTRACTThe effect of furnace grown SiO2 layers on the optical properties of p- on p+ (100) Si substrates are investigated. The real part, n, of the complex refractive index n* = n + ik is calculated for radiation measured in the infra-red (IR) region between 3000 and 8000 cm−1 where the extinction coefficient, k, is negligible. The expression for n is obtained using the Fresnel coefficients for a three medium air-oxide-Si model. Strain in the silicon, which affects n, and caused by the stress in the SiO2 layer, increases with oxide thickness. X-ray diffraction (XRD) was used to measure the strain in Si for oxides layers ranging from native to 5124Å. The data showed a monotonically increasing normal compressive strain, εN (up to 0.47%) with oxide thickness, however, the corresponding change in n due to strain was not well defined. The effect of strain on the direct optical gap, Ed, at 3.46 eV when determined from results of other investigators by electroreflectance, suggests an average shift in Ed of about 25 meV.

Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

Structural and optical properties of Tin Oxide and Indium doped SnO2 thin films deposited by thermal evaporation technique

2016 ◽  
Vol 12 (3) ◽  
pp. 4394-4399
Author(s):  
Sura Ali Noaman ◽  
Rashid Owaid Kadhim ◽  
Saleem Azara Hussain
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Tin Oxide ◽  
Thermal Evaporation ◽  
Pure Sno2 ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Evaporation Technique ◽  
Sno2 Thin Films

Tin Oxide and Indium doped Tin Oxide (SnO2:In) thin films were deposited on glass and Silicon  substrates  by  thermal evaporation technique.  X-ray diffraction pattern of  pure SnO2 and SnO2:In thin films annealed at 650oC and the results showed  that the structure have tetragonal phase with preferred orientation in (110) plane. AFM studies showed an inhibition of grain growth with increase in indium concentration. SEM studies of pure  SnO2 and  Indium doped tin oxide (SnO2:In) ) thin films showed that the films with regular distribution of particles and they have spherical shape.  Optical properties such as  Transmission , optical band-gap have been measured and calculated.

scholarly journals Study on the Electrical, Structural, Chemical and Optical Properties of PVD Ta(N) Films Deposited with Different N2 Flow Rates

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 937
Author(s):  
Yingying Hu ◽  
Md Rasadujjaman ◽  
Yanrong Wang ◽  
Jing Zhang ◽  
Jiang Yan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Photoelectron Spectroscopy ◽  
Crystal Size ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Flow Rates ◽  
X Ray ◽  
N2 Flow Rate

By reactive DC magnetron sputtering from a pure Ta target onto silicon substrates, Ta(N) films were prepared with different N2 flow rates of 0, 12, 17, 25, 38, and 58 sccm. The effects of N2 flow rate on the electrical properties, crystal structure, elemental composition, and optical properties of Ta(N) were studied. These properties were characterized by the four-probe method, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE). Results show that the deposition rate decreases with an increase of N2 flows. Furthermore, as resistivity increases, the crystal size decreases, the crystal structure transitions from β-Ta to TaN(111), and finally becomes the N-rich phase Ta3N5(130, 040). Studying the optical properties, it is found that there are differences in the refractive index (n) and extinction coefficient (k) of Ta(N) with different thicknesses and different N2 flow rates, depending on the crystal size and crystal phase structure.

Rapid Thermal Oxidation for Passivation of Porous Silicon

1994 ◽  
Vol 342 ◽  
Author(s):  
I. BÁrsony ◽  
J.G.E. Klappe ◽  
É. Vázsonyi ◽  
T. Lohner ◽  
M. Fried
Keyword(s):  
Porous Silicon ◽  
Mechanical Stability ◽  
Porous Substrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Tetragonal Lattice ◽  
Optical Heating ◽  
Vertical Inhomogeneity ◽  
Highly Porous

ABSTRACTChemical and mechanical stability of porous silicon layers (PSL) is the prerequisite of any active (luminescent) or passive (e.g. porous substrate) integrated applications. In this work X-ray diffraction (XRD) was used to analyze quantitatively the strain distribution obtained in different morphology PSL that were prepared on (100) p and p+Si substrates. Tetragonal lattice constant distortion can be as high as 1.4% in highly porous “as-prepared” samples. Incoherent optical heating RTO is governed by the absorption in the oxidized specimen. PSL show vertical inhomogeneity according to interpretation of spectroscopic ellipsometry (SE) data. Oxygen incorporation during RTO is controlled by specific surface (in p+ proportional, in p inversely proportional with porosity), while the developing compressive stress depends on pore size, and decreases with porosity in both morphologies.

A Study on the Growth of Cubic GaN Films Using an AlGaAs Buffer Layer Grown on GaAs (100) by Plasma-Assisted Molecular Beam Epitaxy

2000 ◽  
Vol 639 ◽  
Author(s):  
Ryuhei Kimura ◽  
Kiyoshi Takahashi ◽  
H. T. Grahn
Keyword(s):  
Molecular Beam Epitaxy ◽  
Buffer Layer ◽  
Molecular Beam ◽  
High Energy ◽  
Rf Plasma ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cubic Gan

ABSTRACTAn investigation of the growth mechanism for RF-plasma assisted molecular beam epitaxy of cubic GaN films using a nitrided AlGaAs buffer layer was carried out by in-situ reflection high energy electron diffraction (RHEED) and high resolution X-ray diffraction (HRXRD). It was found that hexagonal GaN nuclei grow on (1, 1, 1) facets during nitridation of the AlGaAs buffer layer, but a highly pure, cubic-phase GaN epilayer was grown on the nitrided AlGaAs buffer layer.

Magnetic Anisotropy in Electrodeposited CO Films and spin-valves on Gaas Substrates

1999 ◽  
Vol 562 ◽  
Author(s):  
K. Attenborough ◽  
M. Cerisier ◽  
H. Boeve ◽  
J. De Boeck ◽  
G. Borghs ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Buffer Layer ◽  
Structural Properties ◽  
Easy Axis ◽  
Spin Valve ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cu Films ◽  
Gaas Substrates ◽  
Unique Spin

ABSTRACTWe have studied the magnetic and structural properties of thin electrodeposited Co and Cu layers grown directly onto (100) n-GaAs and have investigated the influence of a buffer layer. A dominant fourfold anisotropy with a uniaxial contribution is observed in 10 nm Co electrodeposited films on GaAs. An easy axis is observed in the [001] GaAs direction with two hard axes of differing coercivities parallel to the [011] and [011] directions. For thicker films the easy axes in the [001] direction becomes less pronounced and the fourfold anisotropy becomes less dominant. Co films of similar thicknesses deposited onto an electrodeposited Cu buffer layer were nearly isotropic. From X-ray diffraction 21 nm Co layers on GaAs were found to be hcp with the c-axis tending to be in the plane of the film. The anisotropy is ascribed to the Co/GaAs interface and is held responsible for the unique spin-valve properties seen recently in electrodeposited Co/Cu films.

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