Nonbirefringent bands in thin films of a copolymer melt: rapid rhythmic crystal growth with an unusual crystal–melt interface

CrystEngComm ◽  
2018 ◽  
Vol 20 (16) ◽  
pp. 2221-2226 ◽  
Author(s):  
Yiguo Li ◽  
Zhilong Yao ◽  
Lin Wu ◽  
Zongbao Wang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Crystal Growth ◽  
Melt Crystallization ◽  
Rhythmic Growth

Rhythmic-growth-induced nonbirefringent bands that are comprised of repetitive stacks of discrete flat-on lamellae along the growth directions are reported in a thin film of an asymmetric PCL-b-PEO during isothermal melt crystallization.

Crystal Growth of β-FeSi2 Thin Film on (100), (110) and (111) Plane of Si and Yittria-stabilized Zirconia Substrates

2006 ◽  
Vol 980 ◽  
Author(s):  
Kensuke Akiyama ◽  
Satoru Kaneko ◽  
Takanori Kiguchi ◽  
Takashi Suemasu ◽  
Takeshi Kimura ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Crystal Growth ◽  
Magnetron Sputtering ◽  
Iron Silicide ◽  
Rf Magnetron Sputtering ◽  
Single Element ◽  
Stabilized Zirconia ◽  
Crystalline Film ◽  
Anions And Cations

AbstractIron silicide thin films were prepared on silicon (Si) and yittria-stabilized zirconia (YSZ) substrates using RF magnetron sputtering and evaporation methods. Epitaxial b-FeSi2 thin films were grown on (100) and (111) planes of Si and YSZ substrates, while noncrystallized films were deposited on (110) plane of both Si and YSZ substrates. The epitaxial relationships between the b-FeSi2 and YSZ were the same as those between b-FeSi2 and Si, in the case of (100) and (111) planes. It is possible that epitaxial b-FeSi2 film can be grown when substrates and b-FeSi2 surfaces consist of either a single element or only cations, while the crystalline film was not shown when either substrate or b-FeSi2 surface consists of a mixture of anions and cations or iron and silicon.

Toward low-cost large-area CIGS thin film III: Effect of Se concentration on crystal growth and defect formation of sequentially electrodeposited CIGS thin films

Solar Energy ◽  
2016 ◽  
Vol 132 ◽  
pp. 547-557 ◽  
Author(s):  
Ming-Hua Yeh ◽  
Shih-Jung Ho ◽  
Guang-Hong Chen ◽  
Chang-Wei Yeh ◽  
Pin-Ru Chen ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Crystal Growth ◽  
Defect Formation ◽  
Low Cost ◽  
Large Area ◽  
Cigs Thin Film

Crystal Quality Improvement of CuInS2 Thin Film by Two Step Fabrication Method with Bismuth Addition

2013 ◽  
Vol 372 ◽  
pp. 563-566
Author(s):  
Shohei Fukamizu ◽  
Daisuke Hironiwa ◽  
Takashi Minemoto
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Crystal Growth ◽  
Film Thickness ◽  
High Efficiency ◽  
Growth Promotion ◽  
Crystal Quality ◽  
Chemical Doping ◽  
Bi Doping

CuInS2 (CIS) is the promising candidate of an absorber layer of high efficiency thin film solar cells. The crystal quality of CIS is one of the important factors for high efficiency. A chemical doping approach using antimony and bismuth (Bi) is well known for improving crystal quality in Cu (In,Ga)Se2 thin films. In this study, the effect of Bi doping on evaporated CIS thin films was investigated. A CIS thin film without Bi doping annealed at 600°C showed small crystal grain size of ~1 μm, which was smaller than the CIS film thickness of 2 μm. The small addition of 50 nm-thick Bi promoted crystal growth and large grain size of greater than 1 μm, which was comparable to the CIS film thickness, was realized. The CIS films without and with Bi addition had surface precipitates identified as Cu-S and Cu-Bi-S compounds, respectively. The crystal growth promotion by Bi addition can be attributed to that the Cu-Bi-S compound which has lower melting point of 470~490°C than that of the Cu-S compound of 507°C acted as flux for crystal growth.

Growth of TiO2–Nb2O5 mixed thin films by metal–organic decomposition

2015 ◽  
Vol 29 (30) ◽  
pp. 1550215 ◽  
Author(s):  
Naoki Nishimoto ◽  
Katsumi Yoshino ◽  
Junko Fujihara
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Crystal Growth ◽  
Sintering Temperature ◽  
Dip Coating ◽  
Coating Materials ◽  
Coating Method ◽  
Nb Content ◽  
Metal Organic ◽  
Organic Decomposition

The influence of mixed metal–organic decomposition (MOD) coating materials has been studied based on the crystal growth of TiO2 and TiO2–Nb2O5 mixed thin films. These thin films were grown on quartz substrates using a dip-coating method. The crystal structures of TiO2 films are well known to depend on sintering temperature, whereas the surface morphologies are not significantly affected by sintering temperature. Nb2O5 was mixed with the TiO2 source material as a possible electron donor. The Nb content of the TiO2–Nb2O5 mixed thin film depended on the Nb mole ratio in the TiO2–Nb2O5 mixed MOD coating material. Large crystal grains were observed with increasing Nb content in the TiO2–Nb2O5 mixed thin film, although Nb was inactive as a donor. It can be concluded that Nb enhances the growth of TiO2 by MOD. This enhancement of crystal growth by the intentional addition of an impurity can be expected to improve the characteristics of other semiconductor materials grown by wet processes.

scholarly journals A Critical Review on Crystal Growth Techniques for Scalable Deposition of Photovoltaic Perovskite Thin Films

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4851
Author(s):  
Mazhar Abbas ◽  
Linxiang Zeng ◽  
Fei Guo ◽  
Muhammad Rauf ◽  
Xiao-Cong Yuan ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Crystal Growth ◽  
High Performance ◽  
Large Scale ◽  
Film Formation ◽  
Perovskite Solar Cells ◽  
Large Area ◽  
Gas Blowing ◽  
Key Steps

Although the efficiency of small-size perovskite solar cells (PSCs) has reached an incredible level of 25.25%, there is still a substantial loss in performance when switching from small size devices to large-scale solar modules. The large efficiency deficit is primarily associated with the big challenge of coating homogeneous, large-area, high-quality thin films via scalable processes. Here, we provide a comprehensive understanding of the nucleation and crystal growth kinetics, which are the key steps for perovskite film formation. Several thin-film crystallization techniques, including antisolvent, hot-casting, vacuum quenching, and gas blowing, are then summarized to distinguish their applications for scalable fabrication of perovskite thin films. In viewing the essential importance of the film morphology on device performance, several strategies including additive engineering, Lewis acid-based approach, solvent annealing, etc., which are capable of modulating the crystal morphology of perovskite film, are discussed. Finally, we summarize the recent progress in the scalable deposition of large-scale perovskite thin film for high-performance devices.

scholarly journals Properties of N-Type GaN Thin Film with Si-Ti Codoping on a Glass Substrate

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 582
Author(s):  
Wei-Sheng Liu ◽  
Yu-Lin Chang ◽  
Chun-Yuan Tan ◽  
Cheng-Ting Tsai ◽  
Hsing-Chun Kuo
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Crystal Growth ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
High Electron ◽  
X Ray ◽  
Glass Substrates ◽  
Tauc Plot ◽  
Measurement Results

In this study, n-type gallium nitride (GaN) films were fabricated by a silicon–titanium (Si-Ti) codoping sputtering technique with a zinc oxide (ZnO) buffer layer on amorphous glass substrates with different post-growth annealing temperatures for optimizing the GaN crystal quality. Si-Ti-codoped n-type GaN films that were thermally annealed at 400 °C had a low thin-film resistivity of 2.6 × 10−1 Ω-cm and a high electron concentration of 6.65 × 1019 cm−3, as determined through Hall measurement. X-ray diffraction (XRD) results revealed a high (002) XRD intensity with a narrow spectral line and a full width at half maximum (FWHM) value that indicated the superior crystal growth of a hexagonal structure of the GaN thin films. In addition, photoluminescence measurement results demonstrated a near-band-edge emission at 365 nm, indicating the crystal growth of GaN thin films on glass substrates. The Burstein–Moss effect was observed in the Tauc plot results, indicating that the Fermi level inside the conduction band moves upward and thus improves the n-type properties of the GaN thin film. X-ray photoelectron spectroscopy measurement results revealed that all atoms doped into the GaN film are present and that both Si and Ti atoms bond with N atoms.

Studies on Water in the Hydration Chamber of a Modified Electron Microscope

1970 ◽  
Vol 28 ◽  
pp. 544-545
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Steady State ◽  
Room Temperature ◽  
Small Mass ◽  
Equilibrium Pressure ◽  
Biological Objects ◽  
Mechanical Pump ◽  
Differential Pumping

Use of the electron microscope to examine wet objects is possible due to the small mass thickness of the equilibrium pressure of water vapor at room temperature. Previous attempts to examine hydrated biological objects and water itself used a chamber consisting of two small apertures sealed by two thin films. Extensive work in our laboratory showed that such films have an 80% failure rate when wet. Using the principle of differential pumping of the microscope column, we can use open apertures in place of thin film windows.Fig. 1 shows the modified Siemens la specimen chamber with the connections to the water supply and the auxiliary pumping station. A mechanical pump is connected to the vapor supply via a 100μ aperture to maintain steady-state conditions.

Observations on the growth of YBa2Cu3O7-δ thin films on MgO by pulsed-laser ablation

1991 ◽  
Vol 49 ◽  
pp. 1068-1069
Author(s):  
M. Grant Norton ◽  
C. Barry Carter
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Laser Ablation ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Laser Ablation Process ◽  
Deposition Parameters

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.

Microstructural characterization of YBa2Cu3O7-x thin films formed by metalorganic CVD

1991 ◽  
Vol 49 ◽  
pp. 1080-1081
Author(s):  
P. Lu ◽  
W. Huang ◽  
C.S. Chern ◽  
Y.Q. Li ◽  
J. Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Film Growth ◽  
Chemical Vapor ◽  
Microstructural Characterization ◽  
Ion Milling ◽  
Conventional Grinding

The YBa2Cu3O7-x thin films formed by metalorganic chemical vapor deposition(MOCVD) have been reported to have excellent superconducting properties including a sharp zero resistance transition temperature (Tc) of 89 K and a high critical current density of 2.3x106 A/cm2 or higher. The origin of the high critical current in the thin film compared to bulk materials is attributed to its structural properties such as orientation, grain boundaries and defects on the scale of the coherent length. In this report, we present microstructural aspects of the thin films deposited on the (100) LaAlO3 substrate, which process the highest critical current density.Details of the thin film growth process have been reported elsewhere. The thin films were examined in both planar and cross-section view by electron microscopy. TEM sample preparation was carried out using conventional grinding, dimpling and ion milling techniques. Special care was taken to avoid exposure of the thin films to water during the preparation processes.

Determination of Stoichiometry of GaAs Component in (Gaas)Ge Epitaxially Grown Thin Films by Electron Microprobe X-Ray Analysis

1990 ◽  
Vol 48 (2) ◽  
pp. 264-265
Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
R. J. Baird
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Compound Semiconductors ◽  
Energy Dispersive Analysis ◽  
X Ray ◽  
Metastable Alloys ◽  
Lower Voltage

The epitaxially grown (GaAs)Ge thin film has been arousing much interest because it is one of metastable alloys of III-V compound semiconductors with germanium and a possible candidate in optoelectronic applications. It is important to be able to accurately determine the composition of the film, particularly whether or not the GaAs component is in stoichiometry, but x-ray energy dispersive analysis (EDS) cannot meet this need. The thickness of the film is usually about 0.5-1.5 μm. If Kα peaks are used for quantification, the accelerating voltage must be more than 10 kV in order for these peaks to be excited. Under this voltage, the generation depth of x-ray photons approaches 1 μm, as evidenced by a Monte Carlo simulation and actual x-ray intensity measurement as discussed below. If a lower voltage is used to reduce the generation depth, their L peaks have to be used. But these L peaks actually are merged as one big hump simply because the atomic numbers of these three elements are relatively small and close together, and the EDS energy resolution is limited.

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