scholarly journals Structural and electronic switching of a single crystal 2D metal-organic framework prepared by chemical vapor deposition

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
F. James Claire ◽  
Marina A. Solomos ◽  
Jungkil Kim ◽  
Gaoqiang Wang ◽  
Maxime A. Siegler ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Single Crystal ◽  
Vapor Deposition ◽  
Metal Organic Framework ◽  
Chemical Vapor ◽  
Scanning Tunneling ◽  
Large Area ◽  
High Quality ◽  
Metal Organic ◽  
Organic Framework

Abstract The incorporation of metal-organic frameworks into advanced devices remains a desirable goal, but progress is hindered by difficulties in preparing large crystalline metal-organic framework films with suitable electronic performance. We demonstrate the direct growth of large-area, high quality, and phase pure single metal-organic framework crystals through chemical vapor deposition of a dimolybdenum paddlewheel precursor, Mo2(INA)4. These exceptionally uniform, high quality crystals cover areas up to 8600 µm2 and can be grown down to thicknesses of 30 nm. Moreover, scanning tunneling microscopy indicates that the Mo2(INA)4 clusters assemble into a two-dimensional, single-layer framework. Devices are readily fabricated from single vapor-phase grown crystals and exhibit reversible 8-fold changes in conductivity upon illumination at modest powers. Moreover, we identify vapor-induced single crystal transitions that are reversible and responsible for 30-fold changes in conductivity of the metal-organic framework as monitored by in situ device measurements. Gas-phase methods, including chemical vapor deposition, show broader promise for the preparation of high-quality molecular frameworks, and may enable their integration into devices, including detectors and actuators.

scholarly journals Catalyst-Assisted Large-Area Growth of Single-Crystal β-Ga2O3 Nanowires on Sapphire Substrates by Metal–Organic Chemical Vapor Deposition

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1031 ◽  
Author(s):  
Chunyang Jia ◽  
Dae-Woo Jeon ◽  
Jianlong Xu ◽  
Xiaoyan Yi ◽  
Ji-Hyeon Park ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Single Crystal ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
Large Area ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Transmission Test

In this work, we have achieved synthesizing large-area high-density β-Ga2O3 nanowires on c-plane sapphire substrate by metal–organic chemical vapor deposition assisted with Au nanocrystal seeds as catalysts. These nanowires exhibit one-dimensional structures with Au nanoparticles on the top of the nanowires with lengths exceeding 6 μm and diameters ranging from ~50 to ~200 nm. The β-Ga2O3 nanowires consist of a single-crystal monoclinic structure, which exhibits strong ( 2 ¯ 01) orientation, confirmed by transmission electronic microscopy and X-ray diffraction analysis. The PL spectrum obtained from these β-Ga2O3 nanowires exhibits strong emissions centered at ~360 and ~410 nm, respectively. The energy band gap of the β-Ga2O3 nanowires is estimated to be ~4.7 eV based on an optical transmission test. A possible mechanism for the growth of β-Ga2O3 nanowires is also presented.

scholarly journals Controlled Epitaxial Growth and Atomically Sharp Interface of Graphene/Ferromagnetic Heterostructure via Ambient Pressure Chemical Vapor Deposition

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3112
Author(s):  
Ruinan Wu ◽  
Yueguo Hu ◽  
Peisen Li ◽  
Junping Peng ◽  
Jiafei Hu ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Single Crystal ◽  
Vapor Deposition ◽  
Ambient Pressure ◽  
Chemical Vapor ◽  
Sharp Interface ◽  
Large Area ◽  
Oriented Growth ◽  
High Quality ◽  
Pressure Chemical

The strong spin filtering effect can be produced by C-Ni atomic orbital hybridization in lattice-matched graphene/Ni (111) heterostructures, which provides an ideal platform to improve the tunnel magnetoresistance (TMR) of magnetic tunnel junctions (MTJs). However, large-area, high-quality graphene/ferromagnetic epitaxial interfaces are mainly limited by the single-crystal size of the Ni (111) substrate and well-oriented graphene domains. In this work, based on the preparation of a 2-inch single-crystal Ni (111) film on an Al2O3 (0001) wafer, we successfully achieve the production of a full-coverage, high-quality graphene monolayer on a Ni (111) substrate with an atomically sharp interface via ambient pressure chemical vapor deposition (APCVD). The high crystallinity and strong coupling of the well-oriented epitaxial graphene/Ni (111) interface are systematically investigated and carefully demonstrated. Through the analysis of the growth model, it is shown that the oriented growth induced by the Ni (111) crystal, the optimized graphene nucleation and the subsurface carbon density jointly contribute to the resulting high-quality graphene/Ni (111) heterostructure. Our work provides a convenient approach for the controllable fabrication of a large-area homogeneous graphene/ferromagnetic interface, which would benefit interface engineering of graphene-based MTJs and future chip-level 2D spintronic applications.

Crack-free high quality 2 μm-thick Al0.5Ga0.5N grown on a Si substrate with a superlattice transition layer

CrystEngComm ◽  
2020 ◽  
Vol 22 (7) ◽  
pp. 1160-1165 ◽  
Author(s):  
Yingnan Huang ◽  
Jianxun Liu ◽  
Xiujian Sun ◽  
Xiaoning Zhan ◽  
Qian Sun ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Transition Layer ◽  
Smooth Surface ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Si Substrate ◽  
High Quality ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

We reported the successful growth of a crack-free high-quality 2 μm-thick Al0.5Ga0.5N film with a smooth surface grown on planar Si by metal–organic chemical vapor deposition.

Epitaxial Growth of “Strain-Free” Indium Oxide Films on (111) Yttria-Stabilized Zirconia by Metal-Organic Chemical Vapor Deposition

2020 ◽  
Vol 1014 ◽  
pp. 22-26
Author(s):  
Yi Zhuo ◽  
Zi Min Chen ◽  
Sheng Dong Zhang
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Thick Layer ◽  
Chemical Vapor ◽  
Yttria Stabilized Zirconia ◽  
Organic Chemical ◽  
Stabilized Zirconia ◽  
High Quality ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

In this work, In2O3 thin films were grown on (111) yttria-stabilized zirconia (YSZ) by metal-organic chemical vapor deposition (MOCVD) at different temperature. It is found that samples grown at low temperature showed lower residual stress but higher mosaicity while high growth temperatures could also cause deterioration in crystal quality due to increasing lattice mismatch. To obtain high quality In2O3 film with low residual strain, a 30-nm thick layer grown at 530 °C was introduced as buffer layer, considering both stress relaxation and crystalline mosaicity. By using two-step growth method, a 400 nm-thick, high quality, near-strain-free In2O3 thin film with the full width at half maximum (FWHM) values of (222) diffraction peaks being as narrow as 648 arcsec was successfully obtained.

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