Effects of Film Interfaces on the Properties of Poly-Si Grown by The Metal-Induced Technique for Solar Cell Applications

2003 ◽  
Vol 796 ◽  
Author(s):  
Chunhai Ji ◽  
Wayne A. Anderson
Keyword(s):  
Seed Layer ◽  
Lattice Mismatch ◽  
Xrd Analysis ◽  
Crystal Defects ◽  
Photon Absorption ◽  
X Ray Diffraction ◽  
Lattice Match ◽  
Silicide Layer ◽  
Layer Sample ◽  
The One

ABSTRACTIn the metal-induced growth (MIG) process, the poly-Si layer hetero-epitaxially grows from a thin silicide layer, formed by reaction of a metal seed-layer and sputtered silicon, due to an extremely close lattice match between silicon and the metal silicide. The produced poly-Si has shown a promising device quality for photovoltaic applications. Recent results show that the interface of the silicide and poly-Si has a significant effect on the properties of the poly-Si which works as an active layer for photon absorption. In the study of the MIG process, two metals were used as a seed-layer, i.e. Ni and Co. Although CoSi2has a larger lattice mismatch with Si (1.2%) than does NiSi2(0.4%), the poly-Si growing from Co has a smoother interface between the poly-Si and silicide, while the one for the Ni seed-layer samples is rather rough. Backscattered XSEM shows that the Ni-contained phase extended into the Si layer by forming long spikes. This might cause crystal defects in the Si layer. The Auger depth profile also showed that the Ni atoms diffuse into the Si layer much more than does the Co. This kind of difference in interface structure causes the different properties of the poly-Si layer. X-ray diffraction (XRD) analysis on the Si layer showed that the Co seed-layer sample had a predominant growth orientation of (220) and the FWHM of 0.2°. The Ni seed-layer samples grew mainly in both <111> and <220> direction, with FWHM of 0.3° and 0.4°, respectively. By comparison, the poly-Si from the Co seed-layer had a higher carrier lifetime of 0.458μs compared to 0.305μs from Ni.

MECHANICAL PROPERTIES OF A POLYURETHANE/MONTMORILLONITE NANOCOMPOSITE FEATURING ORGANOMODIFICATION SYNTHESIZED VIA IN SITU POLYMERIZATION

2015 ◽  
Vol 88 (1) ◽  
pp. 138-146 ◽  
Author(s):  
Rouhollah Bagheri ◽  
Reza Darvishi
Keyword(s):  
Mechanical Properties ◽  
In Situ Polymerization ◽  
Xrd Analysis ◽  
Silicate Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
End Groups ◽  
Layer Sample ◽  
Silicate Layers

ABSTRACT In this study, polyurethane (PU)/organomodified montmorillonite (cloisite®30B) is synthesized via in situ polymerization by reaction of an ether-based prepolymer with the isocyanate end groups and adiamine chain extender (4, 4-methylene-bis(2-chloroaniline)) in the presence of different amounts of nanoparticles dispersed in the prepolymer matrix by an ultrasonic mixer for 1 h. The synthesized polymers are cast on a pretreated carbon steel sheet and cured at 120 °C in an oven. The PU and its composites have been characterized by using Fourier transform infrared spectroscopy, X-ray diffraction (XRD), and mechanical testing. The XRD analysis of the cured samples containing 1 to 3 wt% cloisite30B showed intercalation segments in the silicate layers and exfoliation for 0.5 wt% nanoparticles. The highest mechanical properties were obtained using the cured exfoliated silicate layer sample. A twofold increase in the ultimate tensile strength and a 2.3 times increase in the adhesion strength were found for 0.5 wt% organoclay/PU as compared with that of pure PU. In addition, the exfoliated structure sample exhibited a 16% reduction in abrasion compared with that of pure PU.

Preparation and Characterization of CdSxTe1−x Alloys and Films

2001 ◽  
Vol 668 ◽  
Author(s):  
R.G. Dhere ◽  
D.S. Albin ◽  
S.E. Asher ◽  
H.R. Moutinho ◽  
D. Compton ◽  
...  
Keyword(s):  
High Efficiency ◽  
Lattice Mismatch ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Alloy Films ◽  
Present Generation ◽  
Large Lattice ◽  
Large Lattice Mismatch ◽  
Post Deposition

ABSTRACTIntermixing at the CdS/CdTe interface is considered crucial for the performance of CdTe-based solar cells. High-efficiency devices have been fabricated in spite of large lattice mismatch between CdS and CdTe. Intermixing and formation of CdSxTe1−x alloys in present-generation devices result from high-temperature CdTe deposition and post-deposition CdCl2 treatment. In this paper, we present our work on preparation of CdSxTe1−x-alloy powders and films. In this process, the CdS and CdTe powders are sized and mixed, isostatically pressed into a bar, sealed into closed-quartz ampoules, annealed at temperatures >1000°C, and water quenched. X-ray diffraction (XRD) analysis showed that they contained only distinct phases on S-rich and Te-rich sides of the phase diagram. Recently, two new batches of CdSxTe1−x material, produced by an improved process have been obtained (x =0.71 and x= 0.35 in CdSxTe1−x alloy). Initial XRD results from the films deposited by close spaced sublimation (CSS) using these powders reveal that both samples of bulk powders (prior to CSS deposition) are single-phase and demonstrate CdS-like characteristics (hexagonal). We have deposited CdSxTe1−x-alloy films using these powders. These alloy powders evaporate more congruently as opposed to mixed powders of CdS and CdTe. We will also present results on the structural properties of thin CdSxTe1−x alloy films deposited using these powders by CSS.

Influence of Crystal Defects on the Reflectivity of the Aluminum

2015 ◽  
Vol 756 ◽  
pp. 164-168
Author(s):  
S.P. Umnov ◽  
O.Kh. Asainov ◽  
A.N. Lemachko
Keyword(s):  
Ion Beam ◽  
Xrd Analysis ◽  
Crystal Defects ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Uv Reflectance ◽  
Argon Ion

The effect of ion-assisted deposition of the Al films on their UV reflectance is investigated in this paper. The films' reflectance is measured by a spectrophotometer. The obtained films are examined by using transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), and atomic force microscopy (AFM). The TEM and AFM measurements allow the determination of the size of crystallites in a film and its microstructure. The XRD analysis reveals that the films deposited with argon ion-beam assist are characterized by much higher microstress levels compared to the films deposited without ion assist. The comparison of the Al films’ reflectance measurements indicate that the films with a higher microstress level (hence, higher defect concentration) are characterized by the enhanced reflectance in the UV region. The conducted investigation shows that the defects of the Al films’ crystalline structure affect its optical properties.

DCD and Low T Pl Determination of Bandgap Dependence on Composition for Mocvd Grown InGaAs/InP

1987 ◽  
Vol 102 ◽  
Author(s):  
I. C. Bassignana ◽  
C. J. Miner ◽  
N. Puetz
Keyword(s):  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Epitaxial Layers ◽  
X Ray Diffraction ◽  
Recombination Energy ◽  
Double Crystal ◽  
Lattice Match ◽  
Metal Organic

ABSTRACTThis work reports a detailed study of the bound exciton recombination energy measured by low temperature (7K) photoluminescence, as a function of the relative lattice mismatch between the InGaAs epitaxial layers and the substrate measured by double crystal x-ray diffraction. Nominally undoped lμm and 2μm epitaxial layers of InGaAs/InP were grown by metal organic chemical vapor deposition (MOCVD). All InGaAs epitaxial layers used in this study show a single narrow rocking curve peak (FWHM < 25 arc-sec) and only a single narrow PL peak (FWHM < 2.5 meV). Near lattice match the PL energy varies linearly with the mismatch but the absolute value of the PL energy at lattice match is a function of the type of substrate used.

TEM study of Cosi2 formation via annealing of Co-Ti bilayers on Si

1995 ◽  
Vol 53 ◽  
pp. 464-465
Author(s):  
N. David Theodore ◽  
Andre Vantomme ◽  
Peter Crazier
Keyword(s):  
Thermal Instability ◽  
Lattice Mismatch ◽  
Field Effect Transistors ◽  
Contact Layer ◽  
Interface Roughness ◽  
Oxide Semiconductor ◽  
Surface Layers ◽  
Silicide Layer ◽  
Small Lattice ◽  
Buried Layers

Contact is typically made to source/drain regions of metal-oxide-semiconductor field-effect transistors (MOSFETs) by use of TiSi2 or CoSi2 layers followed by AI(Cu) metal lines. A silicide layer is used to reduce contact resistance. TiSi2 or CoSi2 are chosen for the contact layer because these silicides have low resistivities (~12-15 μΩ-cm for TiSi2 in the C54 phase, and ~10-15 μΩ-cm for CoSi2). CoSi2 has other desirable properties, such as being thermally stable up to >1000°C for surface layers and >1100°C for buried layers, and having a small lattice mismatch with silicon, -1.2% at room temperature. During CoSi2 growth, Co is the diffusing species. Electrode shorts and voids which can arise if Si is the diffusing species are therefore avoided. However, problems can arise due to silicide-Si interface roughness (leading to nonuniformity in film resistance) and thermal instability of the resistance upon further high temperature annealing. These problems can be avoided if the CoSi2 can be grown epitaxially on silicon.

Identification of acid-insoluble filter-plugging compounds and optimal acid-washing procedures for tubular backpulse pressure filters

TAPPI Journal ◽  
2011 ◽  
Vol 10 (1) ◽  
pp. 17-23
Author(s):  
KEVIN TAYLOR ◽  
RICH ADDERLY ◽  
GAVIN BAXTER
Keyword(s):  
Calcium Sulfate ◽  
Membrane Filter ◽  
Sulfamic Acid ◽  
Xrd Analysis ◽  
Metal Sulfides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gypsum Formation ◽  
Acid Washing ◽  
Hydrolysis Of

Over time, performance of tubular backpulse pressure filters in kraft mills deteriorates, even with regular acid washing. Unscheduled filter replacement due to filter plugging results in significant costs and may result in mill downtime. We identified acid-insoluble filter-plugging materials by scanning electron microscope/energy-dispersion X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis in both polypropylene and Gore-Tex™ membrane filter socks. The major filter-plugging components were calcium sulfate (gypsum), calcium phosphate (hydroxylapatite), aluminosilicate clays, metal sulfides, and carbon. We carried out detailed sample analysis of both the standard acid-washing procedure and a modified procedure. Filter plugging by gypsum and metal sulfides appeared to occur because of the acid-washing procedure. Gypsum formation on the filter resulted from significant hydrolysis of sulfamic acid solution at temperatures greater than 130°F. Modification of the acid-washing procedure greatly reduced the amount of gypsum and addition of a surfactant to the acid reduced wash time and mobilized some of the carbon from the filter. With surfactant, acid washing was 95% complete after 40 min.

Chemical and Electrochemical Heteroepitaxial Growth of Chalcogenide Semiconductors from Solutions

1996 ◽  
Vol 451 ◽  
Author(s):  
D. Lincot ◽  
M. J. Furlong ◽  
M. Froment ◽  
R. Cortes ◽  
M. C. Bernard
Keyword(s):  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
Basic Principles ◽  
Lattice Match ◽  
X Ray ◽  
Chalcogenide Semiconductors ◽  
Influence Of Temperature On ◽  
Deposition Processes ◽  
A Site ◽  
Site Selective

ABSTRACTChalcogenide semiconductors have been deposited epitaxially from aqueous solutions either chemically or electrochemically at growth rates of up to 0.7 μmhr−1. After recalling the basic principles of these deposition processes, results are presented concerning chemically deposited CdS on InP, GaP and CuInSe2 substrates, electrodeposited CdTe on InP, and CdSAnP heterostructures. Characterisation of these structures by RHEED, TEM, HRTEM, and glazing angle X ray diffraction allows to analyse the effects of substrate orientation, polarity, lattice match plus the influence of temperature on epitaxial growth. These results are discussed in terms of self organisation and a site selective growth mechanisms due to the free enegy of formation of each compound.

scholarly journals Exo⇔Endo Isomerism, MEP/DFT, XRD/HSA-Interactions of 2,5-Dimethoxybenzaldehyde: Thermal, 1BNA-Docking, Optical, and TD-DFT Studies

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5970
Author(s):  
Nabil Al-Zaqri ◽  
Mohammed Suleiman ◽  
Anas Al-Ali ◽  
Khaled Alkanad ◽  
Karthik Kumara ◽  
...  
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Structural Parameters ◽  
Population Analysis ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Optical Energy Gap ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
Td Dft

The exo⇔endo isomerization of 2,5-dimethoxybenzaldehyde was theoretically studied by density functional theory (DFT) to examine its favored conformers via sp2–sp2 single rotation. Both isomers were docked against 1BNA DNA to elucidate their binding ability, and the DFT-computed structural parameters results were matched with the X-ray diffraction (XRD) crystallographic parameters. XRD analysis showed that the exo-isomer was structurally favored and was also considered as the kinetically preferred isomer, while several hydrogen-bonding interactions detected in the crystal lattice by XRD were in good agreement with the Hirshfeld surface analysis calculations. The molecular electrostatic potential, Mulliken and natural population analysis charges, frontier molecular orbitals (HOMO/LUMO), and global reactivity descriptors quantum parameters were also determined at the B3LYP/6-311G(d,p) level of theory. The computed electronic calculations, i.e., TD-SCF/DFT, B3LYP-IR, NMR-DB, and GIAO-NMR, were compared to the experimental UV–Vis., optical energy gap, FTIR, and 1H-NMR, respectively. The thermal behavior of 2,5-dimethoxybenzaldehyde was also evaluated in an open atmosphere by a thermogravimetric–derivative thermogravimetric analysis, indicating its stability up to 95 °C.

A study on using expanded perlite with hydroxyapatite: Reinforced bio-composites

2021 ◽  
pp. 095441192199656
Author(s):  
Erdoğan Karip ◽  
Mehtap Muratoğlu
Keyword(s):  
Body Fluid ◽  
Xrd Analysis ◽  
Cold Isostatic Pressing ◽  
Expanded Perlite ◽  
X Ray Diffraction ◽  
Pressing Method ◽  
X Ray ◽  
Infra Red ◽  
Ft Ir

People are exposed to different kinds of diseases or various accidents in life. Hydroxyapatite (HA) has been widely employed for bone treatment applications. In this study, HA was extracted from sheep bones. Bio-composites were doped with 1, 5, and 10 wt.% of expanded perlite and 5 wt.% of ZrO2–MgO-P2O5. The bio-composites were prepared by the cold isostatic pressing method (250 MPa) and sintered at 900°C for 1 h. In order to evaluate the characteristics of the bio-composites, microhardness, density, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analyses were carried out on them. Additionally, the specimens whose characteristics were determined were kept in synthetic body fluid (SBF), and their in vitro behavior was examined. As a result, it was observed that microhardness increased as both the weight and the grain size of the expanded perlite were increased. Calcium silicate, tri-calcium phosphate, and hydroxyapatite were observed in the XRD analysis of all samples, and the formation of apatite structures was increased by addition of ZrO2–MgO–P2O5.

scholarly journals ZnOTe Compounds Grown by DC-Magnetron Co-Sputtering

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 570
Author(s):  
Olga Sánchez ◽  
Manuel Hernández-Vélez
Keyword(s):  
Molar Fraction ◽  
Variable Parameter ◽  
Point Of View ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sample Series ◽  
Solid Phases ◽  
The One ◽  
High Bulk ◽  
Substrate Sample

ZnOTe compounds were grown by DC magnetron cosputtering from pure Tellurium (Te) and Zinc (Zn) cathodes in O2/Ar atmosphere. The applied power on the Zn target was constant equal to 100 W, while the one applied on the Te target took two values, i.e., 5 W and 10 W. Thus, two sample series were obtained in which the variable parameter was the distance from the Te targets to the substrate. Sample compositions were determined by Rutherford Backscattering Spectroscopy (RBS) experiments. Structural analysis was done using X-Ray diffraction (XRD) spectrometry and the growth of the hexagonal w-ZnO phase was identified in the XRD spectra. RBS results showed high bulk homogeneity of the samples forming ZnOTe alloys, with variable Te molar fraction (MF) ranging from 0.48–0.6% and from 1.9–3.1% for the sample series obtained at 5 W and 10 W, respectively. The results reflect great differences between the two sample series, particularly from the structural and optical point of view. These experiments point to the possibility of Te doping ZnO with the permanence of intrinsic defects, as well as the possibility of the formation of other Te solid phases when its content increases. The results and appreciable variations in the band gap transitions were detected from Photoluminescence (PL) measurements.

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