Electrochemical deposition of a conducting polymer, poly(thiophene-3-acetic acid): the first observation of individual events of polymer nucleation and two-dimensional layer-by-layer growth

Langmuir ◽  
1992 ◽  
Vol 8 (6) ◽  
pp. 1645-1653 ◽  
Author(s):  
Feng Bin Li ◽  
W. John Albery
Keyword(s):  
Acetic Acid ◽  
Conducting Polymer ◽  
Electrochemical Deposition ◽  
Layer Growth ◽  
Layer By Layer ◽  
Two Dimensional

Layer by layer growth of electroactive conducting polymer/magnetite hybrid assemblies

2013 ◽  
Vol 171 ◽  
pp. 62-68 ◽  
Author(s):  
B. Endrődi ◽  
A. Bíró ◽  
C. Janáky ◽  
I.Y. Tóth ◽  
C. Visy
Keyword(s):  
Conducting Polymer ◽  
Layer Growth ◽  
Layer By Layer ◽  
Hybrid Assemblies

Metal-Organic chemical vapor deposition of BN on sapphire and its heterostructures with 2D and 3D materials

MRS Advances ◽  
2016 ◽  
Vol 1 (32) ◽  
pp. 2273-2283
Author(s):  
Qing Paduano ◽  
Michael Snure
Keyword(s):  
Electron Mobility ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
High Electron Mobility Transistor ◽  
Layer Growth ◽  
Organic Chemical ◽  
Layer By Layer ◽  
High Electron ◽  
Two Dimensional ◽  
Direct Growth

ABSTRACTWe studied MOCVD processing for direct growth of BN on 2” sapphire substrates as a template for heterostructures with two dimensional (2D) and three dimensional (3D) materials. The combined experimental evidence points to three growth modes for BN: self-terminating, 3D random, and layer-by-layer, all of which are dependent on V/III ratio, temperature, pressure, and substrate surface modification via nitridation. At moderate temperature (950-1050°C), BN growth using high V/III ratio is self-terminating, resulting in c-oriented films aligned in-plane with respect to the orientation of the sapphire substrate. BN films grown under low V/III ratios are 3D, randomly oriented, and nano-crystalline. At higher temperature (1100°C), self-terminating growth transitions to a continuous layer-by-layer growth mode. When BN growth is self-terminating, films exhibit atomically smooth surface morphology and highly uniform thickness over a 2” sapphire wafer. Using these BN/sapphire templates we studied the growth of 2D and 2D/3D heterostructures. To study direct growth of 2D on 2D layered material we deposited graphene on BN in a continued process within the same MOCVD system. Furthermore, we explore the growth and nucleation of 3D materials (GaN and AlN) on BN. AlGaN/GaN based high electron mobility transistor (HEMT) structures grown on BN/sapphire exhibited two-dimensional electron gas characteristics at the AlGaN/GaN heterointerface, with room-temperature electron mobility and sheet electron density about 1900cm2/Vs and 1x1013cm-2, respectively.

Rheed Intensity Oscillation During Layer-by-Layer Growth of Bi-Sr-Ca-Cu-O Thin Films

1992 ◽  
Vol 275 ◽  
Author(s):  
K. Yoshikawa ◽  
N. Sasaki
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
High Energy ◽  
Layer Growth ◽  
Layer By Layer ◽  
Two Dimensional ◽  
Growth Interruption ◽  
Layer Deposition ◽  
Unit Cells ◽  
Layered Growth

ABSTRACTUsing in-situ reflection high-energy electron diffraction (RHEED), we studied the growth of Bi-Sr-Ca-Cu-O (BSCCO) thin films prepared by reactive evaporation using layer-by-layer deposition. Bi2Sr2CaCu2Ox(2212) tends to be grown three-dimensionally if it is grown directly on (100) SrTiO3, in contrast to Bi2Sr2CuOx(2201) which is easily grown two-dimensionally on SrTiO3. Two-dimensional 2212 growth can be realized, if a buffer layer of 2201 is deposited on (100) SrTiO3 and growth interruption is utilized after SrO layer deposition. A buffer layer of only two 2201 unit cells improved the surface crystallinity of the substrate for the epitaxial growth of 2212. Growth interruption for two minutes after the 2nd SrO layer in the half unit cell is necessary to keep two-dimensional layered growth. The resulting Tc (zero) is 76 K and Jc (at 4.2 K) is 1.5 × 106 (A/cm2) with these epitaxial films.

Energetics of AlN Epitaxial Wetting Layers on SiC (0001)

1996 ◽  
Vol 449 ◽  
Author(s):  
R. Di Felice ◽  
J. E. Northrup ◽  
J. Neugebauer
Keyword(s):  
First Principles ◽  
Three Dimensional ◽  
Layer Growth ◽  
Layer By Layer ◽  
Two Dimensional ◽  
Charge Accumulation ◽  
Wetting Layer ◽  
Interface Charge ◽  
Wetting Layers

ABSTRACTWe present a first-principles characterization of the initial stages of formation of AlN films on c-plane SiC substrates. Studying the competition between two-dimensional films and three-dimensional islands as a function of Al and N abundances, we find that a two-dimensional film can wet the surface in N-rich conditions. Ordered layer-by-layer growth can proceed to some extent on this wetting layer, and is improved by the formation of an atomically mixed interface which eliminates interface charge accumulation. Our results indicate that the stable AlN films grow in the (0001) orientation on the Si-terminated SiC(0001) substrate.

Formation of Interfacial Dislocations in Hetero-Epitaxial Layers Grown in Two-Dimensional Mode

1995 ◽  
Vol 399 ◽  
Author(s):  
S. Oktyabrsky ◽  
J. Narayan
Keyword(s):  
Compressive Strain ◽  
Elastic Interaction ◽  
Misfit Strain ◽  
Layer Growth ◽  
Dislocation Network ◽  
Misfit Dislocations ◽  
Layer By Layer ◽  
Two Dimensional ◽  
Transmission Electron ◽  
Interfacial Dislocations

ABSTRACTHigh-resolution transmission electron microscopy has been used to study formation of interfacial defects related to misfit strain accommodation in Ge/Si heterostructures (mismatch 4%) grown in the two-dimensional mode. Special emphasis is placed on the conditions leading to a two-dimensional (layer-by-layer) growth mode. We discuss general features of a dislocation tangle resulted from glide-limited plastic relaxation, typical for highly mismatched (001)-diamond and zinc-blende heterostructures. The evolution of the dislocation network as a function of film thickness and thermal annealing is controlled by growth instabilities and dislocation interactions. The observed correlation in distribution of parallel misfit dislocations including pairing (at <2 nm) of misfit segments from intersecting glide planes and rearrangements in a nonequilibrium dislocation network driven by elastic interaction between 60° dislocation segments in the almost relaxed heterostructures are discussed in detail. Pairing of the 60° glide dislocations results either in their combination to form pure edge 90° dislocations or in the dissociation into partials. We propose and experimentally verify a model for the latter process involving the formation of extrinsic stacking faults in the heterolayers under compressive strain.

Temperature Dependence of Critical Thickness for Two Dimensional Growth of GexSi1−x on Si Substrate

1991 ◽  
Vol 220 ◽  
Author(s):  
Xun Wang ◽  
G. L. Zhou ◽  
T. C. Zhou ◽  
C. Sheng ◽  
M. R. Yu
Keyword(s):  
Growth Temperature ◽  
Critical Thickness ◽  
Layer Growth ◽  
Layer By Layer ◽  
Two Dimensional ◽  
Si Substrate ◽  
Lower Growth ◽  
Germanium Content ◽  
Si Substrates ◽  
Molecular Beam Epitaxial

ABSTRACTFor obtaining good structural perfection, the molecular beam epitaxial (MBE) growth of GexSi1−x on Si substrate should not only be kept in the pseudomorphic form but also in layer-by-layer growth stage. We found that the two dimensional layer-by-layer growth of GexSi1−x on Si could persist to a certain deposition thickness, beyond that the transition to islanding growth occurs. The transition thickness is significantly dependent on the growth temperature and germanium content, and is always smaller than the critical thickness of pseudomorphic growth. In order to obtain good crystalline quality in growing GexSi1−x superlattices on Si substrates, the thickness of GexSi1−x layers should be controlled below the transition thickness and lower growth temperature is favorable.

Oblique-incidence Reflectivity Difference (OI-RD) and Leed Studies of Adsorption and Growth of Xe on Nb(110)

2003 ◽  
Vol 780 ◽  
Author(s):  
P. Thomas ◽  
E. Nabighian ◽  
M.C. Bartelt ◽  
C.Y. Fong ◽  
X.D. Zhu
Keyword(s):  
Transition Layer ◽  
Layer Growth ◽  
Flow Mode ◽  
Layer By Layer ◽  
Zeroth Order ◽  
Step Flow ◽  
Low Energy Electron Diffraction ◽  
Oriented Film ◽  
Low Energy Electron

AbstractWe studied adsorption, growth and desorption of Xe on Nb(110) using an in-situ obliqueincidence reflectivity difference (OI-RD) technique and low energy electron diffraction (LEED) from 32 K to 100 K. The results show that Xe grows a (111)-oriented film after a transition layer is formed on Nb(110). The transition layer consists of three layers. The first two layers are disordered with Xe-Xe separation significantly larger than the bulk value. The third monolayer forms a close packed (111) structure on top of the tensile-strained double layer and serves as a template for subsequent homoepitaxy. The adsorption of the first and the second layers are zeroth order with sticking coefficient close to one. Growth of the Xe(111) film on the transition layer proceeds in a step flow mode from 54K to 40K. At 40K, an incomplete layer-by-layer growth is observed while below 35K the growth proceeds in a multilayer mode.

scholarly journals Modeling the Layer-by-Layer Growth of HKUST-1 Metal-Organic Framework Thin Films

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1631
Author(s):  
Qiang Zhang ◽  
Yohanes Pramudya ◽  
Wolfgang Wenzel ◽  
Christof Wöll
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Deposition Rate ◽  
Layer Growth ◽  
Coarse Grained ◽  
Structural Defects ◽  
Effect Of Temperature ◽  
Layer By Layer ◽  
Reactant Concentration ◽  
Metal Organic

Metal organic frameworks have emerged as an important new class of materials with many applications, such as sensing, gas separation, drug delivery. In many cases, their performance is limited by structural defects, including vacancies and domain boundaries. In the case of MOF thin films, surface roughness can also have a pronounced influence on MOF-based device properties. Presently, there is little systematic knowledge about optimal growth conditions with regard to optimal morphologies for specific applications. In this work, we simulate the layer-by-layer (LbL) growth of the HKUST-1 MOF as a function of temperature and reactant concentration using a coarse-grained model that permits detailed insights into the growth mechanism. This model helps to understand the morphological features of HKUST-1 grown under different conditions and can be used to predict and optimize the temperature for the purpose of controlling the crystal quality and yield. It was found that reactant concentration affects the mass deposition rate, while its effect on the crystallinity of the generated HKUST-1 film is less pronounced. In addition, the effect of temperature on the surface roughness of the film can be divided into three regimes. Temperatures in the range from 10 to 129 °C allow better control of surface roughness and film thickness, while film growth in the range of 129 to 182 °C is characterized by a lower mass deposition rate per cycle and rougher surfaces. Finally, for T larger than 182 °C, the film grows slower, but in a smooth fashion. Furthermore, the potential effect of temperature on the crystallinity of LbL-grown HKUST-1 was quantified. To obtain high crystallinity, the operating temperature should preferably not exceed 57 °C, with an optimum around 28 °C, which agrees with experimental observations.

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