Growth dynamics of C60 thin films: effect of molecular structure

The surface morphology and growth behavior of fullerene thin films have been studied by atomic force microscopy and height difference correlation function analysis. In contrast to the large growth exponents (beta) previously reported for other organic semiconductor thin-film materials, a relatively small beta value of 0.39±0.10 was determined. Simulations of (1+1)-dimensional surface lateral diffusion models indicate that the evolution of deep grain boundaries leads to a rapid increase in beta. We suggest that the commonly observed large beta values for organic thin films are due to their intrinsically anisotropic molecular structures and hence different stacking directions between crystallite domains

Ideation as an intellectual information acquisition and use context: Investigating game designers’ information-based ideation behavior

Human Information Behavior (HIB) research commonly examines behavior in the context of why information is acquired and how it will be used, but usually at the level of the work or everyday-life tasks the information will support. HIB has not been examined in detail at the broader contextual level of intellectual purpose (i.e. the higher-order conceptual tasks the information was acquired to support). Examination at this level can enhance holistic understanding of HIB as a ‘means to an intellectual end’ and inform the design of digital information environments that support information interaction for specific intellectual purposes. We investigate information-based ideation (IBI) as a specific intellectual information acquisition and use context by conducting Critical Incident-style interviews with ten game designers, focusing on how they interact with information to generate and develop creative design ideas. Our findings give rise to a framework of their ideation-focused HIB, which systems designers can leverage to reason about how best to support certain behaviors to drive design ideation. These findings emphasize the importance of intellectual purpose as a driver for acquisition and desired outcome of use

Automated Array Assembly Task In-depth Study of Silicon Wafer Surface Texturizing

Several aspects of silicon wafer surface texturizing were studied. A low cost cleaning method that utilizes recycled Freon in an ultrasonic vapor degreaser to remove organic and inorganic contaminants from the surface of silicon wafers as received from silicon suppliers was investigated. The use of clean dry air and high throughout wafer batch drying techniques was shown to lower the cost of wafer drying. A two stage texturizing process was examined for suitability in large scale production. Also, an in-depth gettering study with the two stage texturizing process was performed for the enhancement of solar cell efficiency, minimization of current versus voltage curve dispersion, and improvement in process reproducibility. The 10% efficiency improvement goal was exceeded for the near term implementation of flat plate photovoltaic cost reduction

Production of Millisecond Dips in Sco X-1 Count Rates by Dead Time Effects

Chang et al. (2006) reported millisecond duration dips in the X-ray intensity of Sco X-1 and attributed them to occultations of the source by small trans-Neptunian objects (TNOs). We have found multiple lines of evidence that these dips are not astronomical in origin, but rather the result of high-energy charged particle events in the RXTE PCA detectors. Our analysis of the RXTE data indicates that at most 10% of the observed dips in Sco X-1 could be due to occultations by TNOs, and, furthermore, we find no positive or supporting evidence for any of them being due to TNOs. We therefore believe that it is a mistake to conclude that any TNOs have been detected via occultation of Sco X-1.Comment: Submitted to ApJ; uses emulateapj.cls, 8 pages with 8 figure

Rapid Thermal Processing (RTP) of semiconductors in space

The progress achieved on the project entitled 'Rapid Thermal Processing of Semiconductors in Space' for a 12 month period of activity ending March 31, 1993 is summarized. The activity of this group is being performed under the direct auspices of the ROMPS program. The main objective of this program is to develop and demonstrate the use of advanced robotics in space with rapid thermal process (RTP) of semiconductors providing the test technology. Rapid thermal processing is an ideal processing step for demonstration purposes since it encompasses many of the characteristics of other processes used in solid state device manufacturing. Furthermore, a low thermal budget is becoming more important in existing manufacturing practice, while a low thermal budget is critical to successful processing in space. A secondary objective of this project is to determine the influence of microgravity on the rapid thermal process for a variety of operating modes. In many instances, this involves one or more fluid phases. The advancement of microgravity processing science is an important ancillary objective

Photon Frequency Mode Matching using Acousto-Optic Frequency Beam Splitters

It is a difficult engineering task to create distinct solid state single photon sources which nonetheless emit photons at the same frequency. It is also hard to create entangled photon pairs from quantum dots. In the spirit of quantum engineering we propose a simple optical circuit which can, in the right circumstances, make frequency distinguishable photons frequency indistinguishable. Our circuit can supply a downstream solution to both problems, opening up a large window of allowed frequency mismatches between physical mechanisms. The only components used are spectrum analysers/prisms and an Acousto-Optic Modulator. We also note that an Acousto-Optic Modulator can be used to obtain Hong-Ou-Mandel two photon interference effects from the frequency distinguishable photons generated by distinct sources.Comment: 4 pages, 4 figure

Macroscopic and microscopic studies of electrical properties of very thin silicon dioxide subject to electrical stress

The electrical characteristics of various size tunnel switch diode devices, composed of Al/SiO2/n-Si/p+-Si layers, which operate with a range of parameters (such as current densities in excess of 104 A/cm2) that stress the oxide layer far beyond the levels used in typical thin oxide metal-oxide semiconductor research have been examined. It is found that the first time a large current and electric field are applied to the device, a "forming" process enhances transport through the oxide in the vicinity of the edges of the gate electrode, but the oxide still retains its integrity as a tunnel barrier. The device operation is relatively stable to stresses of greater than 107 C/cm2 areally averaged, time-integrated charge injection. Duplication and characterization of these modified oxide tunneling properties was attempted using scanning tunneling microscopy (STM) to stress and probe the oxide. Electrical stressing with the STM tip creates regions of reduced conductivity, possibly resulting from trapped charge in the oxide. Lateral variations in the conductivity of the unstressed oxide over regions roughly 20–50 nm across were also found