3-D Simulator of Laser Crystallization for Polycrystalline-Silicon Thin-Film Transistors
A 3-D simulator of laser crystallization for polycrystalline-silicon thin-film transistors has been developed. Random nucleation, crystal growth velocity, latent heat emission, and partial crystallization are modeled, and a 2-D algorithm is extended to a 3-D algorithm. The <formula formulatype="inline"><tex Notation="TeX">$\mu$</tex></formula>-Czochralski technique is analyzed using the 3-D simulator, and it is found that the grain size becomes large when the initial temperature is high after the laser irradiation.
Microstructure characterization of location-controlled Si-islands crystallized by excimer laser in the μ-Czochralski (grain filter) process
Abstract Microstructure of location-controlled grains by μ-Czochralski process was characterized with electron backscattering diffraction (EBSD) and transmission electron microscopy (TEM). We confirmed that defects in the location-controlled grain are mainly Σ 3 twin boundary generating from near the rim of the grain filter, while random grain boundaries hardly exist. Dependence of the population was investigated on process parameters. We found that most of the Σ 3 twin boundaries have {1 1 1} facet plane, which, in same case, are massed with a nano-meter spacing. Σ 3 twin boundaries having facet planes {1 1 2} and {1 1 1}/{1 1 5} were also found to exist.
Urea removal strategies for dialysate regeneration in a wearable artificial kidney.
The availability of a wearable artificial kidney (WAK) that provides dialysis outside the hospital would be an important advancement for dialysis patients. The concept of a WAK is based on regeneration of a small volume of dialysate in a closed-loop. Removal of urea, the primary waste product of nitrogen metabolism, is the major challenge for the realization of a WAK since it is a molecule with low reactivity that is difficult to adsorb while it is the waste solute with the highest daily molar production. Currently, no efficient urea removal technology is available that allows for miniaturization of the WAK to a size and weight that is acceptable for patients to carry. Several urea removal strategies have been explored, including enzymatic hydrolysis by urease, electro-oxidation and sorbent systems. However, thus far, these methods have toxic side effects, limited removal capacity or slow removal kinetics. This review discusses different urea removal strategies for application in a wearable dialysis device, from both a chemical and a medical perspective.