scholarly journals Study of the Annealing Effect on the γ-Phase Aluminum Oxide Films Prepared by the High-Vacuum MOCVD System

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 389
Author(s):  
Zhao Li ◽  
Yangmei Xin ◽  
Yunyan Liu ◽  
Huiqiang Liu ◽  
Dan Yu ◽  
...  
Keyword(s):  
Aluminum Oxide ◽  
High Vacuum ◽  
Visible Region ◽  
Optoelectronic Devices ◽  
Wavelength Region ◽  
Chemical Vapor ◽  
Optical Transmittance ◽  
Organic Chemical ◽  
Semiconductor Films ◽  
Good Transparency

γ-phase aluminum oxide (γ-Al2O3) films are grown on MgO (100) wafers by metal organic chemical vapor deposition (MOCVD). Post-annealing process is conducted to study the influence of annealing temperature on the properties of the films. Structural analyses indicate that all the deposited and annealed films present a preferred growth orientation of γ-Al2O3 (220) along the MgO (200) direction. And the film annealed at 1100 °C exhibits the best film quality compared with those of the films grown and annealed at other temperatures. Scanning electron microscopy measurements also imply the best surface morphology for the γ-Al2O3 film annealed at 1100 °C, which is in good accordance with the structural analyses. Optical transmittance spectra show good transparency for all the deposited and annealed films in the visible wavelength region with an average transmittance value of 83.5%. The optical bandgaps are estimated to be in the range of 5.56–5.79 eV for the deposited and annealed films. Semiconductor films with high optical transmittance in the visible region as well as wide bandgaps are appropriate for the manufacture of transparent optoelectronic devices and ultraviolet optoelectronic devices.

scholarly journals Oxide p-n Heterojunction of Cu2O/ZnO Nanowires and Their Photovoltaic Performance

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Seung Ki Baek ◽  
Ki Ryong Lee ◽  
Hyung Koun Cho
Keyword(s):  
Solar Cell ◽  
Photovoltaic Performance ◽  
Wavelength Region ◽  
Chemical Vapor ◽  
Zno Nanowires ◽  
Organic Chemical ◽  
Glass Substrates ◽  
Constant Ph ◽  
Ito Glass ◽  
P Type

Oxide p-n heterojunction devices consisting of p-Cu2O/n-ZnO nanowires were fabricated on ITO/glass substrates and their photovoltaic performances were investigated. The vertically arrayed ZnO nanowires were grown by metal organic chemical vapor deposition, which was followed by the electrodeposition of the p-type Cu2O layer. Prior to the fabrication of solar cells, the effect of bath pH on properties of the absorber layers was studied to determine the optimal condition of the Cu2O electrodeposition process. With the constant pH 11 solution, the Cu2O layer preferred the (111) orientation, which gave low electrical resistivity and high optical absorption. The Cu2O (pH 11)/ZnO nanowire-based solar cell exhibited a higher conversion efficiency of 0.27% than the planar structure solar cell (0.13%), because of the effective charge collection in the long wavelength region and because of the enhanced junction area.

scholarly journals Atomically thin three-dimensional membranes of van der Waals semiconductors by wafer-scale growth

2019 ◽  
Vol 5 (7) ◽  
pp. eaaw3180 ◽  
Author(s):  
Gangtae Jin ◽  
Chang-Soo Lee ◽  
Xing Liao ◽  
Juho Kim ◽  
Zhen Wang ◽  
...  
Keyword(s):  
Van Der Waals ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Semiconductor Films ◽  
Scale Growth ◽  
Wafer Scale ◽  
Equilibrium Limit ◽  
Si Substrates ◽  
3D Texture

We report wafer-scale growth of atomically thin, three-dimensional (3D) van der Waals (vdW) semiconductor membranes. By controlling the growth kinetics in the near-equilibrium limit during metal-organic chemical vapor depositions of MoS2 and WS2 monolayer (ML) crystals, we have achieved conformal ML coverage on diverse 3D texture substrates, such as periodic arrays of nanoscale needles and trenches on quartz and SiO2/Si substrates. The ML semiconductor properties, such as channel resistivity and photoluminescence, are verified to be seamlessly uniform over the 3D textures and are scalable to wafer scale. In addition, we demonstrated that these 3D films can be easily delaminated from the growth substrates to form suspended 3D semiconductor membranes. Our work suggests that vdW ML semiconductor films can be useful platforms for patchable membrane electronics with atomic precision, yet large areas, on arbitrary substrates.

Preparation and Characterization of High Mobility Nb-Doped SnO2 Transparent Conducting Films

2020 ◽  
Vol 993 ◽  
pp. 869-875
Author(s):  
Lin An He ◽  
Cai Na Luan ◽  
Di Wang ◽  
Yong Le ◽  
Jin Ma
Keyword(s):  
Hall Mobility ◽  
High Mobility ◽  
Chemical Vapor ◽  
Growth Direction ◽  
Light Transmittance ◽  
Organic Chemical ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Metal Organic ◽  
Good Transparency

Metal organic chemical vapor deposition (MOCVD) was employed for the preparation of niobium (Nb)-doped SnO2 films on SiO2 glass substrates. The structure, optical and electrical properties of the Nb-doped SnO2 films were systemically studied. The X-ray diffraction results indicated that the polycrystalline rutile SnO2 films were obtained with a preferred SnO2 [110] growth direction. Among which, the 5.4 at.% Nb-doped SnO2 film showed the lowest resistivity of 1.0×10-3 Ω∙cm and the highest Hall mobility of 74 cm2∙V-1∙s-1. The average visible light transmittance of the 5.4 at.% Nb-doped SnO2 sample was more than 79%. The obtained Nb-doped SnO2 films exhibited low resistivity, high Hall mobility and good transparency, which might have wide applications in electric and photoelectric devices.

Characteristics of Fluorine-Doped Tin Oxide Thin Films on Poly Ethylene Terephthalate (PET) Substrate

2007 ◽  
Vol 544-545 ◽  
pp. 949-952 ◽  
Author(s):  
Yun Ho Kook ◽  
Ji Hun Park ◽  
Dong Jin Byun ◽  
Joong Kee Lee
Keyword(s):  
Thin Films ◽  
Tin Oxide ◽  
Sulfur Hexafluoride ◽  
Carbon Deposition ◽  
Electron Cyclotron Resonance ◽  
Chemical Vapor ◽  
Optical Transmittance ◽  
Organic Chemical ◽  
Hydro Carbon ◽  
Polyethylene Terephthalate Substrate

Fluorine-doped tin oxide (FTO) films on PET (Polyethylene Terephthalate) substrate were prepared by the electron cyclotron resonance-metal organic chemical vapor deposition (ECRMOCVD) under an Ar-O2-H2 atmosphere. The used tin and fluorine precursor are TMT (tetramethyltin) and sulfur hexafluoride (SF6), respectively. The hydrogen content plays an important role to control the optical and electrical characteristics of the films. The HF etching effect was clearly observed with increase of H2/TMT mole ratio, on the other hand the hydro-carbon deposition increased with decrease of H2/TMT mole ratio. Therefore the optimum H2 content can be determined by the counter balance effect between HF etching and hydro-carbon deposition. The obtained optimum SnO2: F thin films exhibited over 90 % of optical transmittance at wavelength range from 380 to 780 nm and c.a. 6×10-3 ohm ·cm of electrical resistivity at 1.25 H2/TMT mole ratio.

scholarly journals Mixed Phases at the Bottom Interface of Si-Doped AlGaN Epilayers of Optoelectronic Devices

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Chen-hui Yu ◽  
Qing-zhou Luo ◽  
Xiang-dong Luo ◽  
Pei-sheng Liu
Keyword(s):  
Optoelectronic Devices ◽  
Chemical Vapor ◽  
Hydrogen Atmosphere ◽  
Organic Chemical ◽  
Lower Growth ◽  
Nucleation Layer ◽  
Raman Scattering Spectroscopy ◽  
Bottom Interface ◽  
Metal Organic ◽  
Si Doped

This paper presents an analysis of crystalline structures of Si-doped Al0.4Ga0.6N layers grown on not-intentionally doped AlGaN buffer layer with an AlN nucleation layer by metal organic chemical vapor deposition. Weak cubic Al0.4Ga0.6N (002) and (103) reflection peaks are observed in high-resolution XRDθ/2θscans and cubic Al0.4Ga0.6N (LO) mode in Raman scattering spectroscopy. These cubic subgrains are localized at the bottom interface of Si-doped layer due to the pulsed lower growth temperature and rich hydrogen atmosphere at the start of silane injection. Their appearance has no direct relationship with the buffer and nucleation layer. This study is helpful not only to understand fundamental properties of high aluminum content Si-doped AlGaN alloys but also to provide specific guidance on the fabrication of multilayer optoelectronic devices where weak cubic subgrains potentially occur and exert complicated influences on the device performance.

scholarly journals Исследование возможностей метода газофазной эпитаксии из металлорганических соединений для изготовления тонких слоев InAs/GaSb

2019 ◽  
Vol 89 (10) ◽  
pp. 1592
Author(s):  
Р.В. Левин ◽  
Б.В. Пушный ◽  
И.В. Федоров ◽  
А.А. Усикова ◽  
В.Н. Неведомский ◽  
...  
Keyword(s):  
Optoelectronic Devices ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Bandgap Engineering ◽  
Infrared Wavelength ◽  
Semiconductor Structures ◽  
Transmission Electron ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Electro Luminescence

Capabilities of Metal Organic Chemical Vapor Deposition (MOCVD) method for fabrication of multi-layer InAs/GaSb structures with thin (1-2 nm) layers on GaSb substrates were studied. Properties of fabricated structures were studied by transmission electron microscopy and photo- and electro-luminescence. It was found that during growth, two solid solutions GaInAsSb of different compositions were formed in the active region of the structures. The system obtained is characterized by emission at the wavelength of 4.96 µm at the temperature 77 K. Our results demonstrate new capabilities of MOCVD method for bandgap engineering of semiconductor structures based on InAs/GaSb and designed for optoelectronic devices for infrared wavelength range.

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