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.

Characterization of Ferroelectric Thin Film PLZT(9/65/35) on R-Plane Sapphire

1990 ◽  
Vol 200 ◽  
Author(s):  
S. Krishnakumar ◽  
S.C. Esener ◽  
C. Fan ◽  
V.H. Ozguz ◽  
M.A. Title ◽  
...  
Keyword(s):  
Lattice Mismatch ◽  
Ferroelectric Thin Film ◽  
Spatial Light Modulators ◽  
Light Modulators ◽  
Large Lattice ◽  
Large Lattice Mismatch ◽  
Deposited Films ◽  
Deposition Techniques ◽  
Post Deposition

ABSTRACTThe deposition of ferroelectric PLZT on r-plane sapphire using R-F Triode Magnetron Sputtering is reported. R-plane (1102) sapphire is chosen, in spite of its large lattice mismatch to PLZT, because of its capability of integrating MOS silicon circuits with PLZT modulators. Perovskite PLZT films with the desired composition (9/65/35) are obtained using co-deposition techniques around 500°C and post deposition annealing at 650°C. The deposited films exhibit good optical and electro-optical properties. The room temperature dielectric constant of the films was 1800 at 10 Khz. The refractive index of the films was in the range 2.2–2.5. The films showed a quadratic E-O effect with R=0.6×10−16 m2/V2. The films are promising for smart Spatial Light Modulators (SLM) applications.

Properties of the magnetoresistive La0.8Sr0.2MnO3 film and integration with PbZr0.52 Ti0.48O3 ferroelectrics

2000 ◽  
Vol 617 ◽  
Author(s):  
Fumiaki Mitsugi ◽  
Tomoaki Ikegami ◽  
Kenji Ebihara ◽  
J. Narayan ◽  
A. M. Grishin
Keyword(s):  
Lattice Mismatch ◽  
Laser Energy ◽  
Single Crystal Substrate ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Colossal Magnetoresistive ◽  
Lsmo Film ◽  
Large Lattice ◽  
Crystal Substrate ◽  
Large Lattice Mismatch

AbstractThe colossal magnetoresistive La0.8Sr0.2MnO3 (LSMO) thin film was prepared on the MgO (100) single crystal substrate using KrF excimer pulsed laser deposition technique. The LSMO film deposited at the substrate temperature of 850 °C, oxygen pressure of 500 mTorr and laser energy density of 2 J/cm2(5 Hz) showed the resistivity peak temperature (Tp) of 330 K and the magnetoresi stance change of 15 %(H=0.7 T) at the room temperature. The large lattice mismatch with the substrate increased Tp and decreased the resistivity of the LSMO film.The X-ray diffraction measurement for the PbZr0.52Ti0.48O3 (PZT) / LSMO heterostructures indicated both c-axis and in- plane orientation, with the good PZT surface morphology.

scholarly journals Self-Assembled BaTiO3-MnZnFe2O4Nanocomposite Films

2012 ◽  
Vol 2012 ◽  
pp. 1-5
Author(s):  
Guo Yu ◽  
Feiming Bai ◽  
Huaiwu Zhang
Keyword(s):  
Remanent Polarization ◽  
Lattice Mismatch ◽  
Nanocomposite Films ◽  
X Ray Diffraction ◽  
Mnzn Ferrite ◽  
Large Lattice ◽  
Out Of Plane ◽  
Large Lattice Mismatch ◽  
Plane Direction ◽  
Self Assembled

Self-assembled nanocomposite BaTiO3-Mn0.4Zn0.87Fe2O4magnetodielectric films have been grown on (001)-oriented SrTiO3substrates by a pulsed laser deposition method. High resolution X-ray diffraction shows that both BaTiO3and MnZn-ferrite phases are epitaxial along the out-of-plane direction with a 0–3 composite structure in spite of very large lattice mismatch. The magnetic, ferroelectric, and dielectric properties of the nanocomposite films are reported. A saturated magnetization of 330 emu/cc and double remanent polarization of 40 μC/cm2were obtained. Structural and compositional factors limiting the effective permeability and the dielectric constant will be discussed.

Characterization of Interfacial Structure in Large Lattice Mismatch Heteroepitaxy: Ag/Si (111)

1990 ◽  
Vol 209 ◽  
Author(s):  
D.C. McKenna ◽  
G.-C. Wang ◽  
K. Rajan
Keyword(s):  
Lattice Mismatch ◽  
Interfacial Structure ◽  
Epitaxial Relationship ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Interfacial Structures ◽  
Large Lattice ◽  
Large Lattice Mismatch ◽  
Diffraction Patterns

ABSTRACTThe interfacial structure of a large lattice mismatched (˜25%) (111) Ag-Si system was studied by using transmission electron diffraction (SADP - Selected Area Diffraction Pattern). The epitaxial films of Ag (600–1200Å) were grown by MBE on flat Si(111) and misoriented Si(1ll) surfaces. We have examined the interfacial structures of the Ag on 2° misoriented Si(111) using diffraction patterns of cross sectional view. Through a detail analysis of thelocation and shape of the diffraction spots, we can determine the epitaxial relationship between Ag and Si, the small tilt angle of Ag(111) planes withrespect to the misoriented Si(111), the period of the finite terrace size of the misoriented Si substrate, and the size of the ordered region in the Ag film. The O-lattice analysis developed by Bollmann has beenapplied to this interface andthe result is compared with the SADP observation.

Structural Effects in Al(111)/Si(111) Heteroepitaxy by Partially Ionized Beam Deposition α

1988 ◽  
Vol 116 ◽  
pp. 465-470 ◽  
Author(s):  
A. S. Yapsir ◽  
C.-H. Choi ◽  
S. N. Yang ◽  
T.-M. Lu ◽  
M. Madden ◽  
...  
Keyword(s):  
Single Crystal ◽  
Lattice Mismatch ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Atom Ratio ◽  
Transmission Electron ◽  
Large Lattice ◽  
Large Lattice Mismatch ◽  
Partially Ionized ◽  
Acceleration Voltage

AbstractSingle crystal Al(111) films were grown on Si(111) surface at room temperature under a conventional vacuum condition using the partially ionized beam (PIB) deposition technique. The Al films were deposited with an ion to atom ratio of about 0.3% and an acceleration voltage of 1 kV. Transmission electron microscopy (TEM) analysis showed that the as-deposited films were single crystal with certain density of dislocation networks. These dislocations disappeared following a heat treatment at 450°C for 30 min. From X-ray diffraction and TEM patterns, it was observed that the Al(111) was aligned to the substrate with Al<1l0>//Si<1l0>. Possible mechanisms of the PIB epitaxial growth and a novel structural defect that is unique to this large lattice mismatch system are discussed.

Heteroepitaxial growth and structural analysis of epitaxial α–Fe2O3(1010) on TiO2(001)

2005 ◽  
Vol 20 (5) ◽  
pp. 1250-1256 ◽  
Author(s):  
Joshua R. Williams ◽  
Chongmin Wang ◽  
Scott A. Chambers
Keyword(s):  
Lattice Mismatch ◽  
High Energy ◽  
Unit Cell ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Pole Figures ◽  
Large Lattice ◽  
Large Lattice Mismatch

We grew epitaxial α–Fe2O3(1010) on TiO2(001) rutile by oxygen plasma-assisted molecular-beam epitaxy. High-resolution transmission electron microscopy (HRTEM), reflection high-energy electron diffraction (RHEED), and x-ray diffraction pole figures confirm that the film is composed of four different in-plane orientations rotated by 90° relative to one another. For a given Fe2O3 unit cell, the lattice mismatch along the parallel [0001]Fe2O3 and [100]TiO2 directions is nominally +67%. However, due to a 3-fold repetition of the slightly distorted square symmetry of anion positions within the Fe2O3 unit cell, there is a coincidental anion alignment along the [0001]Fe2O3 and [100]TiO2 directions, which results in an effective lattice mismatch of only −0.02% along this direction. The lattice mismatch is nearly 10% in the orthogonal [1120]Fe2O3 and [100]TiO2 directions. The film is highly ordered and well registered to the substrate despite a large lattice mismatch in one direction. The film grows in registry with the substrate along the parallel [0001]Fe2O3 and [100]TiO2 directions and nucleates dislocations along the orthogonal [1120]Fe2O3 [100]TiO2 directions.

Epitaxial Dielectric Planarization for Multilayer HTSC Structures

1994 ◽  
Vol 341 ◽  
Author(s):  
Bertha P. Chang ◽  
Paul C. Mcintyre ◽  
Neville Sonnenberg ◽  
Michael J. Cima
Keyword(s):  
Lattice Mismatch ◽  
Ion Beam ◽  
Thick Layer ◽  
Normal Incidence ◽  
X Ray Diffraction ◽  
Ion Beam Assisted Deposition ◽  
Surface Steps ◽  
Large Lattice ◽  
Large Lattice Mismatch ◽  
Planarization Process

AbstractYttria-stabilized ZrO2 (YSZ) and CeO2 thin films were deposited on patterned (001) YSZ and (001) LaAIO3 substrates, respectively, using ion beam assisted deposition (IBAD) at normal incidence and an ion beam energy of 500eV. All deposition took place at 600°C. An initial 1000Å thick layer was evaporated at 0.2Å/s before beginning IBAD at rates of 0.3Å/s for YSZ and between 0.8Å/s and 1.2Å/s for CeO2. X-ray diffraction shows the YSZ films to grow epitaxially. The planarization mechanism for IBAD YSZ is similar to that previously observed for if-bias sputtering. CeO2 grows epitaxially on LaA103 but a second polycrystalline phase grows preferentially over the surface steps and inhibits the planarization process. The emergence of this phase appears to be related to highly incoherent growth of CeO2 over the stepped edges, which in turn is a function of the large lattice mismatch between CeO2 and LaA1O3 in the [001] direction.

Fabrication and Characterization of CuInS2 Sensitized TiO2 Electrodes Based on Improved SILAR Process

2013 ◽  
Vol 745-746 ◽  
pp. 478-484 ◽  
Author(s):  
Feng Jiao Mei ◽  
Qing Cui Wan ◽  
An Ping ◽  
Hua Liao ◽  
Xue Qing Xu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
High Efficiency ◽  
Photovoltaic Performance ◽  
X Ray Diffraction ◽  
Cyclic Voltammetry Measurement ◽  
Vis Spectroscopy ◽  
Sensitized Solar Cells ◽  
Post Deposition

CuInS2quantum dots have been deposited onto mesoporous TiO2films on TCO glass substrate via successive ionic layer absorption and reaction process (SILAR) by using three different routes and post-deposition annealing in sulfur ambiance. The influence of the deposition sequence of the In-S and Cu-S on the microstructure of CuInS2sensitized TiO2electrodes and the photovoltaic performance of the solar cells have been investigated. The microstructure of CuInS2sensitized TiO2electrodes has been investigated by using X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analysis. The optical absorption property of the electrodes has been detected by using UV-Vis spectroscopy, and the photovoltaic performance of CuInS2quantum dots sensitized solar cells has been determined by cyclic voltammetry measurement. It has been found that when the Cu-S was deposited prior to In-S, the chalcopyrite phase CuInS2could not be observed due to the sublimation of InxS during the annealing under low pressure. A small amount of CuInS2has been detected when In-S and Cu-S was deposited alternately onto the TiO2films. However, chalcopyrite phase CuInS2can be obtained when In-S was deposited prior to Cu-S, and a relative high efficiency of ca. 0.92% (Voc= 0.35V, Jsc= 8.49 mA·cm-2, FF = 0.31) has been achieved via SILAR without KCN treatment and rapid thermal annealing.

scholarly journals Enhanced luminescence/photodetecting bifunctional devices based on ZnO:Ga microwire/p-Si heterojunction by incorporating Ag nanowires

2021 ◽  
Author(s):  
Mingming Jiang ◽  
Yang Liu ◽  
Ruiming Dai ◽  
Kai Tang ◽  
Peng Wan ◽  
...  
Keyword(s):  
Band Gap ◽  
Carrier Mobility ◽  
Lattice Mismatch ◽  
Semiconductor Materials ◽  
Large Lattice ◽  
Ag Nanowires ◽  
Large Lattice Mismatch ◽  
Enhanced Luminescence ◽  
Indirect Band Gap

Suffering from the indirect band gap, low carrier mobility, and large lattice mismatch with other semiconductor materials, one of the current challenges in Si-based materials and structures is to prepare...

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