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Deposition Chamber (deposition + chamber)

Distribution by Scientific Domains

Polymers and Materials Science	80%

Selected Abstracts

Highly Efficient p-i-n and Tandem Organic Light-Emitting Devices Using an Air-Stable and Low-Temperature-Evaporable Metal Azide as an n-Dopant

ADVANCED FUNCTIONAL MATERIALS, Issue 11 2010
Kyoung Soo Yook
Abstract Cesium azide (CsN3) is employed as a novel n-dopant because of its air stability and low deposition temperature. CsN3 is easily co-deposited with the electron transporting materials in an organic molecular beam deposition chamber so that it works well as an n-dopant in the electron transport layer because its evaporation temperature is similar to that of common organic materials. The driving voltage of the p-i-n device with the CsN3 -doped n-type layer and a MoO3 -doped p-type layer is greatly reduced, and this device exhibits a very high power efficiency (57,lm W,1). Additionally, an n-doping mechanism study reveals that CsN3 was decomposed into Cs and N2 during the evaporation. The charge injection mechanism was investigated using transient electroluminescence and capacitance,voltage measurements. A very highly efficient tandem organic light-emitting diodes (OLED; 84,cd A,1) is also created using an n,p junction that is composed of the CsN3 -doped n-type organic layer/MoO3 p-type inorganic layer as the interconnecting unit. This work demonstrates that an air-stable and low-temperature-evaporable inorganic n-dopant can very effectively enhance the device performance in p-i-n and tandem OLEDs, as well as simplify the material handling for the vacuum deposition process. [source]

Nanocrystalline Tin Oxide Thin Films via Liquid Flow Deposition

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2003
Sitthisuntorn Supothina
Nanocrystalline films of SnO2 were deposited by liquid flow deposition (LFD), i.e., by flowing aqueous solutions of SnCl4·5H2O and HCl over single-crystalline silicon substrates at 80°C. The substrates were either oxidized and fully hydrolyzed (bare silicon) or oxidized, hydrolyzed, and then coated with siloxy-anchored organic self-assembled monolayers (SAMs). Continuous, adherent films formed on sulfonate- and thioacetate-functionalized SAMs; adherent but sometimes discontinuous films formed on bare silicon and methyl-functionalized SAMs. The films contained equiaxed cassiterite crystals, ,4,10 nm in size. The film thickness increased linearly with deposition time. The maximum growth rate observed was 85 nm·h,1 on sulfonate SAM, and the maximum film thickness obtained was 1 ,m. A new dimensionless parameter, the normalized residence time, ,, was introduced for the purpose of interpreting the influence of solution conditions (i.e., degree of supersaturation, as controlled via pH, and tin concentration) and flow characteristics (flow rate and the configuration of the deposition chamber) on the growth rate in LFD processes. The results were consistent with a particle attachment mechanism for film growth and inconsistent with heterogeneous nucleation on the substrate. [source]

Plasma-Assisted Atomic Layer Deposition of Al2O3 at Room Temperature

PLASMA PROCESSES AND POLYMERS, Issue S1 2009
Tommi O. Kääriäinen
Abstract A new design of plasma source has been used for the plasma-assisted atomic layer deposition (PA-ALD) of Al2O3 films at room temperature. In this PA-ALD reactor the plasma is generated by capacitive coupling directly in the deposition chamber adjacent to the substrate but can be separated from it by a grid to reduce the ion bombardment while maintaining the flow of radicals directly to the substrate surface. During the ALD cycle a mixture of nitrogen and argon was introduced into the reactor to act as a purge gas between precursor pulses and to facilitate the generation of a plasma during the plasma cycle. Sequential exposures of TMA and excited O2 precursors were used to deposit Al2O3 films on Si(100) substrates. A plasma discharge was activated during the oxygen gas pulse to form radicals in the reactor space. The experiments showed that the growth rate of the film increased with increasing plasma power and with increasing O2 pulse length before saturating at higher power and longer O2 pulse length. The growth rate saturated at the level of 1.78 Å·cycle,1. EDS analysis showed that the films were oxygen rich and had carbon as an impurity. This can be explained by the presence of bonds between hydrocarbons from the unreacted TMA precursor and excess oxygen in the film. ATR-FTIR spectroscopy measurements indicated a change in growth mechanism when the distance between the location of the radical generation and the substrate was varied. A similar effect was observed with the use of different plasma power levels. [source]

Cell deposition system based on laser guidance

BIOTECHNOLOGY JOURNAL, Issue 9 2006
Russell K. Pirlo
Abstract We have designed a laser cell deposition system that employs the phenomenon of laser guidance to place single cells at specific points in a variety of in vitro environments. Here, we describe the components of the system: the laser optics, the deposition chamber, the microinjection cell feeding system and our custom system control software application. We discuss the requirements and challenges involved in laser guidance of cells and how our present system overcomes these challenges. We demonstrate that the patterning system is accurate within one micrometer by repeatedly depositing polymer microspheres and measuring their position. We demonstrate its ability to create highly defined living patterns of cells by creating a defined pattern of neurons with neurite extensions displaying normal function. We found that the positional accuracy of our system is smaller than the variations in cell size and pattern disruptions that occur from normal cell movement during substrate adhesion. The laser cell deposition system is a potentially useful tool that can be used to achieve site- and time-specific placement of an individual cell in a cell culture for the systematic investigation of cell-cell and cell-extracellular matrix interactions. [source]

4H SiC Epitaxial Growth with Chlorine Addition

CHEMICAL VAPOR DEPOSITION, Issue 8-9 2006
F. La
Abstract The growth rate of a 4H-SiC epitaxial layer has been increased by a factor of 19 (up to 112,,m h,1) with respect to the standard process, with the introduction of HCl in the deposition chamber. The epitaxial layers grown with the addition of HCl has been characterized by electrical, optical, and structural characterization methods. The effects of various deposition parameters on the epitaxial growth process have been described, and an explanation of this behavior in terms of the diffusion coefficient on the surface, Ds, and the ratio between the characteristic times, ,D:,G, has been provided. The diodes, manufactured on the epitaxial layer grown with the addition of HCl at 1600,°C, have electrical characteristics comparable with the standard epitaxial process. This process is very promising for high-power devices with a breakdown voltage of 10,kV. [source]