AlGaN/GaN multiple quantum wells grown by using atomic layer deposition technique

2008 ◽  
Vol 1068 ◽  
Author(s):  
Ming-Hua Lo ◽  
Zhen-Yu Li ◽  
Shih-Wei Chen ◽  
Jhih-Cang Hong ◽  
Ting-Chang Lu ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Quantum Wells ◽  
Atomic Layer ◽  
Atomic Force Microscope Image ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Atomic Force ◽  
Transmission Electron ◽  
Layer Deposition

ABSTRACTIn this work, we report on the growth of ultraviolet (UV) AlGaN/GaN multiple quantum wells (MQWs) structure using atomic layer deposition (ALD) technique. The AlGaN/GaN MQW sample grown on the sapphire substrate consisted of three GaN QWs and four AlGaN barriers comprised AlN/GaN superlattices (SLs). The root-mean-square value of the surface morphology was only 0.35 nm observed from the atomic force microscope image and no crack was found on the surface. Both of the high resolution X-ray diffraction curves and transmission electron microscope images showed sharp interfaces between SLs layers and QWs with good periodicity. These results demonstrate that the ALD could be a very useful technique for controlling the crystalline quality and thickness of the III-nitride epilayer.

Optical characterization of type-II ZnO/ZnS multiple quantum wells grown by atomic layer deposition

2020 ◽  
Vol 694 ◽  
pp. 137740 ◽  
Author(s):  
Mostafa Afifi Hassan ◽  
Aadil Waseem ◽  
Muhammad Ali Johar ◽  
Sou Young Yu ◽  
June Key Lee ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Quantum Wells ◽  
Atomic Layer ◽  
Optical Characterization ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Type Ii ◽  
Layer Deposition

High quality ultraviolet AlGaN∕GaN multiple quantum wells with atomic layer deposition grown AlGaN barriers

2008 ◽  
Vol 93 (13) ◽  
pp. 131116 ◽  
Author(s):  
Zhen-Yu Li ◽  
Ming-Hua Lo ◽  
C. T. Hung ◽  
Shih-Wei Chen ◽  
Tien-Chang Lu ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Quantum Wells ◽  
Atomic Layer ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
High Quality ◽  
Layer Deposition

AlGaN/GaN multiple quantum wells grown by atomic-layer deposition

2008 ◽  
Author(s):  
M. H. Lo ◽  
Z. Y. Li ◽  
J. R. Chen ◽  
T. S. Ko ◽  
T. C. Lu ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Quantum Wells ◽  
Atomic Layer ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Layer Deposition

scholarly journals Direct Epitaxial Nanometer-Thin InN of High Structural Quality on 4H-SiC by Atomic Layer Deposition

2020 ◽  
Author(s):  
Chih-Wei Hsu ◽  
Petro Deminskyi ◽  
Ivan Martinovic ◽  
Ivan G. Ivanov ◽  
Justinas Palisaitis ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Indium Nitride ◽  
Atomic Layer ◽  
Structural Quality ◽  
High Electron ◽  
X Ray Diffraction ◽  
High Quality ◽  
Subsequent Formation ◽  
Transmission Electron ◽  
Layer Deposition

<div>Indium nitride (InN) is a highly promising material for high frequency electronics given its</div><div>low band gap and high electron mobility. The development of InN-based devices is hampered</div><div>by the limitations in depositing very thin InN films of high quality. We demonstrate growth of</div><div>high-structural-quality nanometer thin InN films on 4H-SiC by atomic layer deposition (ALD).</div><div>High resolution X-ray diffraction and transmission electron microscopy show epitaxial growth</div><div>and an atomically sharp interface between InN and 4H-SiC. The InN film is fully relaxed already after a few atomic layers and shows a very smooth morphology where the low surface</div><div>roughness (0.14 nm) is found to reproduced sub-nanometer surface features of the substrate. Raman measurements show an asymmetric broadening caused by grains in the InN film. Our results show the potential of ALD to prepare high quality nanometer-thin InN films for subsequent formation of heterojunctions.</div>

Ti Coating of Nanocrystalline Diamond by Atomic Layer Deposition

2006 ◽  
Vol 304-305 ◽  
pp. 48-51 ◽  
Author(s):  
Jian Bing Zang ◽  
Jing Lu ◽  
Yan Hui Wang ◽  
X.H. Qi ◽  
Yun Gang Yuan
Keyword(s):  
Atomic Layer Deposition ◽  
Polycrystalline Diamond ◽  
High Strength ◽  
Atomic Layer ◽  
Nanocrystalline Diamond ◽  
X Ray Diffraction ◽  
Diamond Surfaces ◽  
Transmission Electron ◽  
Layer Deposition ◽  
Binary Reaction

Nanocrystalline diamond compact possesses not only the advantageous performance of polycrystalline diamond but also the high strength and the high toughness of nano-ceramics. However, single-phase nanocrystalline diamond compact is very difficult to sinter because of a huge amount of oxygen-containing and nitrogen-containing functional groups absorbed on the surface of nanocrystalline diamond. In this paper, atomic layer deposition (ALD) method has been used to coat nanocrystalline diamond with titanium, which will promote the bonding of nanocrystalline diamond as the bond in polycrystalline diamond. In vacuum, the H2 and TiCl4 reactants were employed alternately in an ABAB… binary reaction sequence to achieve Ti layer, which reacted with diamond matrix and formed TiC in the coating, realizing strong chemical bonding between the coating and the diamond. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were utilized to study the structure and the morphology of the coating. The results confirmed the formation of titanium carbide at the depositing temperature 500°C. The darker spots and strips observed on nanocrystalline diamond particles by TEM were proved to be TiC and the nucleation and subsequent growth of TiC preferentially occurred in the defects as twin zones and dislocation areas on diamond surfaces.

scholarly journals “Intelligent” Pt Catalysts Based on Thin LaCoO3 Films Prepared by Atomic Layer Deposition

Inorganics ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 113 ◽  
Author(s):  
Xinyu Mao ◽  
Alexandre C. Foucher ◽  
Eric A. Stach ◽  
Raymond J. Gorte
Keyword(s):  
Atomic Layer Deposition ◽  
Co Adsorption ◽  
Atomic Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Highly Active ◽  
Transmission Electron ◽  
Layer Deposition ◽  
Scanning Transmission ◽  
Water Gas

LaCoO3 films were deposited onto MgAl2O4 powders by atomic layer deposition (ALD) and then used as catalyst supports for Pt. X-ray diffraction (XRD) showed that the 0.5 nm films exhibited a perovskite structure after redox cycling at 1073 K, and scanning transmission electron microscopy and elemental mapping via energy-dispersive X-ray spectroscopy (STEM/EDS) data demonstrated that the films covered the substrate uniformly. Catalysts prepared with 3 wt % Pt showed that the Pt remained well dispersed on the perovskite film, even after repeated oxidations and reductions at 1073 K. Despite the high Pt dispersion, CO adsorption at room temperature was negligible. Compared with conventional Pt on MgAl2O4, the reduced forms of the LaCoO3-containing catalyst were highly active for the CO oxidation and water gas shift (WGS) reactions, while the oxidized catalysts showed much lower activities. Surprisingly, the reduced catalysts were much less active than the oxidized catalysts for toluene hydrogen. Catalysts prepared from thin films of Co3O4 or La2O3 exhibited properties more similar to Pt/MgAl2O4. Possible reasons for how LaCoO3 affects properties are discussed.

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