Mocvd SrS:Ce for Applications in Electroluminescent Devices

1997 ◽  
Vol 471 ◽  
Author(s):  
D. Endisch ◽  
K. Barth ◽  
J. Lau ◽  
G. Peterson ◽  
A. E. Kaloyeros ◽  
...  
Keyword(s):  
Process Development ◽  
Process Integration ◽  
Low Cost ◽  
Chemical Vapor ◽  
High Growth ◽  
Film Structure ◽  
High Growth Rate ◽  
Organic Chemical ◽  
Glass Substrates ◽  
Full Color

ABSTRACTSrS:Ce is an important material for full color electroluminescent (EL) flat panel displays. Using a combination of SrS:Ce/ZnS:Mn and appropriate color filters high quality full color displays have been demonstrated [1]. Major issues for commercially viable process integration of SrS:Ce are the combination of high luminance, high growth rate, and process temperatures below 600°C for compatibility with low cost glass substrates. This work describes the process development and optimization of metal-organic chemical vapor deposition (MOCVD) of SrS:Ce. MOCVD is a promising candidate for deposition of SrS:Ce because it can provide the required growth rates and allows control of crystal structure and stoichiometry. Growth of SrS:Ce was performed in the temperature range from 400°C to 530°C using Sr(tmhd)2, Ce(tmhd)4, and H2S as precursors. The structure of the SrS:Ce was found to be strongly dependent on the H2S flow. A brightness of 15 fL and an efficiency of 0.22 lm/W has been achieved (40 V above threshold voltage, 60 Hz AC). Film analysis included Rutherford backscattering (RBS), X-ray diffraction (XRD), atomic force microscopy (AFM), and EL measurements. Results on the correlation between process parameters, film structure, grain size and EL performance will be presented.

Near-Infrared Spectroscopy with a Dispersive Waveguide Device

1997 ◽  
Vol 51 (6) ◽  
pp. 880-882 ◽  
Author(s):  
Brian R. Stallard ◽  
Robert K. Rowe ◽  
Arnold J. Howard ◽  
G. Ronald Hadley ◽  
Gregory A. Vawter ◽  
...  
Keyword(s):  
Near Infrared ◽  
Low Cost ◽  
Ion Beam ◽  
Chemical Vapor ◽  
Discrete Source ◽  
Ethanol Solution ◽  
Organic Chemical ◽  
Ion Beam Etching ◽  
Spectral Dispersion ◽  
Metal Organic

Miniature, low-cost sensors are in demand for a variety of applications in industry, medicine, and environmental sciences. As a first step in developing such a sensor, we have etched a grating into a GaAs rib waveguide to serve as a wavelength-dispersive element. The device was fabricated with the techniques of metal-organic chemical vapor deposition, electron-beam lithography, optical lithography, and reactive ion-beam etching. While full integration is the eventual goal of this work, for the present, a functional spectrometer was constructed with the addition of a discrete source, sample cell, lenses, and detector. The waveguide spectrometer has a spectral resolution of 7.5 nm and a spectral dispersion of 0.11°/ nm. As presently configured, it functions in the spectral range of 1500 to 1600 nm. A demonstration of the analytical capability of the waveguide spectrometer is presented. The problem posed is the determination of diethanol amine in an ethanol solution (about 10 to 100 g/L). This procedure involves the detection of the first overtone of the NH stretch at 1545 nm in a moderately absorbing solvent background. The standard error of prediction for the determination was 5.4 g/L.

Developing Monolithically Integrated CdTe Devices Deposited by AP-MOCVD

2013 ◽  
Vol 1538 ◽  
pp. 275-280
Author(s):  
S.L. Rugen-Hankey ◽  
V. Barrioz ◽  
A. J. Clayton ◽  
G. Kartopu ◽  
S.J.C. Irvine ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Thin Film Deposition ◽  
Deposition Process ◽  
Film Deposition ◽  
Aluminosilicate Glass ◽  
Organic Chemical ◽  
Large Area ◽  
Monolithically Integrated ◽  
Glass Substrates ◽  
Laser Scribing

ABSTRACTThin film deposition process and integrated scribing technologies are key to forming large area Cadmium Telluride (CdTe) modules. In this paper, baseline Cd1-xZnxS/CdTe solar cells were deposited by atmospheric-pressure metal organic chemical vapor deposition (AP-MOCVD) onto commercially available ITO coated boro-aluminosilicate glass substrates. Thermally evaporated gold contacts were compared with a screen printed stack of carbon/silver back contacts in order to move towards large area modules. P2 laser scribing parameters have been reported along with a comparison of mechanical and laser scribing process for the scribe lines, using a UV Nd:YAG laser at 355 nm and 532 nm fiber laser.

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.

Guiding Principle to Develop Intrinsic Microcrystalline Silicon Absorber Layer For Solar Cell By Hot-Wire Cvd

2001 ◽  
Vol 664 ◽  
Author(s):  
A. R. Middya ◽  
U. Weber ◽  
C. Mukherjee ◽  
B. Schroeder
Keyword(s):  
Growth Rate ◽  
Solar Cell ◽  
Cell Structure ◽  
Short Circuit ◽  
Chemical Vapor ◽  
High Growth ◽  
High Growth Rate ◽  
Open Circuit ◽  
Hot Wire ◽  
Microcrystalline Silicon

ABSTRACTWe report on ways to develop device quality microcrystalline silicon (μc-Si:H) intrinsic layer with high growth rate by hot-wire chemical vapor deposition (HWCVD). With combine approach of controlling impurities and moderate H-dilution [H2/SiH4 ͌ 2.5], we developed, for the first time, highly photosensitive (103 μc-Si:Hfilms with high growth rate (>1 nm/s); the microstructure of the film is found to be close to amorphous phase (fc ͌ 46 ̻± 5%). The photosensitivity systematically decreases with fc and saturates to 10 for fc> 70%. On application of these materials in non-optimized pin [.proportional]c-Si:H solar cell structure yields 700 mV open-circuit voltage however, surprisingly low fill factor and short circuit current. The importance of reduction of oxygen impurities [O], adequate passivation of grain boundary (GB) as well as presence of inactive GB of (220) orientation to achieve efficient [.proportional]c-Si:H solar cells are discussed.

Understanding MOCVD Gas Chemistry to Reduce the Cost of Ownership for GaN LED and AsP CPV Technologies

2012 ◽  
Vol 1396 ◽  
Author(s):  
E.A. Armour ◽  
B. Mitrovic ◽  
A. Zhang ◽  
C. Ebert ◽  
M. Pophristic ◽  
...  
Keyword(s):  
Growth Rates ◽  
Light Emitting Diode ◽  
Phase Particle ◽  
Chemical Vapor ◽  
High Growth ◽  
Compound Semiconductors ◽  
Deposition Efficiency ◽  
Organic Chemical ◽  
Primary Metal ◽  
The Cost

ABSTRACTAs compound semiconductors continue to make inroads into common electronic devices, it is critically important to lower the cost of the primary metal-organic chemical vapor deposition (MOCVD) epitaxial process, which creates the foundation for the devices. Both GaN-based light-emitting diode (LED) and AsP-based concentrator photovoltaic (CPV) markets have been focused on simultaneous cost-reduction, cycle time reductions, and device efficiency improvements, which can be realized utilizing higher growth rates and operating pressures. To achieve these goals, it has become increasingly important to understand the underlying growth mechanisms that drive the chemistry within the MOCVD process.Higher growth rates and higher operating pressures both result in parasitic gas-phase particle formation, which degrades the physical, electrical and optical properties of the deposited layers. In extreme cases, it can reduce the deposition efficiency to the point where increasing the reactant constituents results in reduced growth rates. In this paper, we will examine the tradeoffs that need to be made to achieve good crystal quality with abrupt interfaces, smooth surface morphology, and good minority carrier properties for films deposited at high growth rates and high pressure. While exceptional device performance has been achieved for both GaN-based LEDs and AsP-based CPV cells, it is primarily cost that is limiting full-scale adoption of compound semiconductors into these potentially enormous markets.

Halide-CVD Growth of Bulk SiC Crystals

2006 ◽  
Vol 527-529 ◽  
pp. 21-26 ◽  
Author(s):  
A.Y. Polyakov ◽  
Mark A. Fanton ◽  
Marek Skowronski ◽  
Hun Jae Chung ◽  
Saurav Nigam ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
High Growth ◽  
High Growth Rate ◽  
Flow Ratio ◽  
Novel Approach ◽  
Cvd Growth ◽  
Electron And Hole Traps ◽  
Separate Injection

A novel approach to the high growth rate Chemical Vapor Deposition of SiC is described. The Halide Chemical Vapor Deposition (HCVD) method uses SiCl4, C3H8 (or CH4), and hydrogen as reactants. The use of halogenated Si source and of separate injection of Si and C precursors allows for preheating of source gases without causing premature chemical reactions. The stoichiometry of HCVD crystals can be controlled by changing the C/Si flow ratio and can be kept constant throughout growth, in contrast to the Physical Vapor Transport technique. HCVD was demonstrated to deposit high crystalline quality, very high purity 4H- and 6H-SiC crystals with growth rates comparable to other bulk SiC growth techniques. The densities of deep electron and hole traps are determined by growth temperature and C/Si ratio and can be as low as that found in standard silane-based CVD epitaxy. At high C/Si flow ratio, the resistivity of HCVD crystals exceeds 105 _cm. These characteristics make HCVD an attractive method to grow SiC for applications in high-frequency and/or high voltage devices.

RuO2 films by metal-organic chemical vapor deposition

1993 ◽  
Vol 8 (10) ◽  
pp. 2644-2648 ◽  
Author(s):  
Jie Si ◽  
Seshu B. Desu
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Film Structure ◽  
Organic Chemical ◽  
Dilute Gas ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

Pure and conducting RuO2 thin films were successfully deposited on Si, SiO2/Si, and quartz substrates at temperatures as low as 550 °C by a hot wall metal-organic chemical vapor deposition (MOCVD). Bis(cyclopentadienyl)ruthenium, Ru(C5H5)2, was used as the precursor. An optimized MOCVD process for conducting RuO2 thin films was established. Film structure was dependent on MOCVD process parameters such as bubbler temperature, dilute gas flow rates, deposition temperature, and total pressure. Either pure RuO2, pure Ru, or a RuO2 + Ru mixture was obtained under different deposition conditions. As-deposited pure RuO2 films were specular, crack-free, and well adhered on the substrates. The Auger electron spectroscopy depth profile showed good composition uniformity across the bulk of the films. The MOCVD RuO2 thin films exhibited a resistivity as low as 60 μω-cm. In addition, the reflectance of RuO2 in the NIR region had a metallic character.

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