1,720,997 research outputs found
In situ crystal growth imaging during explosive crystallization
No full textExplosive crystallization of amorphous germanium of 0.89 and 1.80 microns in thickness deposited on quartz substrates was investigated. A scalloped, mixed, and columnar regime was observed. In situ images captured using dark field imaging reveal the shape of the explosive crystallization front. Crystallization was induced by a frequency tripled Nd:YAG laser (λ = 355 nm) focused to a tight line. A second Nd:YAG laser was frequency doubled (λ = 532 nm) and used as an illumination source for two time resolved pictures. The shape and speed of the explosive crystallization front is observed for various heat loss parameters and crystallization regimes and is generally in good agreement with the literature. Surface morphology is inspected by Atomic Force Microscopy (AFM) after explosive crystallization has completed.N
Low temperature laser processing for the application in flexible & stretchable electronics
No full textNanomaterials show various interesting unique thermal characteristics such as size dependent melting temperature drop, which can be used to develop plastic compatible low temperature metal patterning process. Focused laser as a local heat source can further reduce the processing temperature or induced localized thermochemical reaction. In this talk, recent research development and trend in nanomaterial based low temperature laser thermal engineering as well as applications will be discussed. © 2015 IEEE.N
A PLANAR, INTEGRATED TOTAL INTERNAL REFLECTION SENSOR FOR BIOFOULING DETECTION
No full textA planar, integrated total internal reflection (TIR) sensor for the characterizations of biofouling has been demonstrated based on angular interrogation of Fraunhofer diffraction. This sensor is made of a two-mask process to have optical prism and built-in waveguides of 4×0.25μm2 in cross section area. The core and cladding layer of the waveguide are made of silicon nitride and silicon dioxide, respectively and a 780nm in wavelength light source is used in the experiments. Water, ethanol, acetone and glycerol, have all been tested to illustrate the basic refractive index sensing principle of the prototype sensor. Biofouling measurements show that after been immersed into milk as the testing liquid, the surface refractive index of a prototype TIR sensor shifted continuously to as much as 0.0089 for a 9-hour test. As such, this technique could be useful to various biofouling control and monitoring applications, including water desalination, medical, marine and electronic device industries.Y
Pulsed laser annealing of semiconductor structures for functional devices
No full textWe review our progress on the laser processing of semiconductor microstructures and nanostructures for functional devices. Fundamental research conducted to understand the melt-mediated phase transformations induced by nanosecond laser irradiation in thin semiconductor films is presented. A detailed experimental study analyzed the physical mechanisms of the explosive crystallization in amorphous germanium that produces large area self-sustained crystal growth. The double laser crystallization method that combines a nanosecond laser pulse and a modulated microsecond laser beam was shown to produce ultra-large grain polycrystalline silicon, enabling fabrication of thin film transistor devices of high performance from amorphous silicon films. The crystal growth process was imaged by temporally resolved photography. Non-melt Excimer Laser annealing of thin silicon-oninsulator films for dopant activation was demonstrated. Applying multiple laser pulses below the melting threshold effected solid phase annealing of the single crystalline silicon films. Semiconductor nanowires are one-dimensional nano-structures that have displayed the potential to be used with low-cost flexible plastic substrates for applications such as large-area displays and sensor arrays. The excimer laser annealing of silicon nanowires is demonstrated as an alternative to conventional thermal annealing for dopant activation. The optical absorption of the nanowires is discussed and the effect of parameters such as fluence and number of pulses is investigated. The interaction of laser pulses with silicon nanowires is investigated through numerical simulations. (Figure Presented) Schematic depiction of pulsed laser annealing of generic semiconductor structures. Specific structures are shown in bottom inset circles. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.N
Smart Wristband: Touch-and-Motion–Tracking Wearable 3D Input Device for Smart Glasses
No full textThe smart wristband is a novel type of wearable input device for smart glasses, and it can control multi-dimensional contents by using touch and motion. The smart wristband uses a touch-and-motion-tracking system with a touch screen panel (TSP) and inertial measurement unit (IMU) to help users control the smart glasses' interface accurately and quickly without environmental noise, distortion, and multi-leveled pattern recognition tasks. This paper presents the availability and usability of the smart glasses; how exactly and quickly users can manipulate the smart glasses' multi-dimensional contents and augmented reality (AR) system by selecting, moving, and changing contents via touching and dragging a finger and rotating the wrist; the device's point-and-click capacity; and its navigation, program switchover, zoom in and out, undo and redo for interactions, and 3D virtual object manipulation aspects for application. © 2014 Springer International Publishing Switzerland.Y
Simulation of organic vapor-jet printing: effect of carrier gas temperature for pentacene thin-film formation
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