We have experimentally and theoretically developed a unique thermally stimulated midinfrared source that emits radiation within a narrow range of wavelengths (δλ/λ⩽0.2). The emission wavelengths are defined by the periodicity of a metal coated silicon–air photonic crystal etched into the emitter surface. The lattice of the holes in the metal mediate the coupling of light into discrete surface plasmon states. This yields surfaces with spectrally nonuniform infrared reflection properties where over much of the IR 90+% of photons are reflected yet, in a narrow spectral region, 90% absorption is observed. Transfer matrix calculations simulate well the position and strength of the absorption features. This technology will afford tunable infrared emitters with high power in a narrow spectral band that are critical for sensing, spectroscopy, and thermophotovoltaic applications.

GaAs layers grown by molecular beam epitaxy (MBE) at substrate temperatures between 200 and 300 °C were studied using transmission electron microscopy (TEM), x-ray diffraction, and electron paramagnetic resonance (EPR) techniques. High-resolution TEM cross-sectional images showed a high degree of crystalline perfection of these layers. For a layer grown at 200 °C and unannealed, x-ray diffraction revealed a 0.1% increase in the lattice parameter in comparison with bulk GaAs. For the same layer, EPR detected arsenic antisite defects with a concentration as high as 5×1018 cm−3. This is the first observation of antisite defects in MBE-grown GaAs. These results are related to off-stoichiometric, strongly As-rich growth, possible only at such low temperatures. These findings are of relevance to the specific electrical properties of low-temperature MBE-grown GaAs layers.

Etching of Si in a variety of solutions is known to cause staining. These stain layers consist of porous material similar to that produced by anodic etching of Si in HF solutions. We have observed photoluminescence peaked in the red from stain-etched Si wafers of different dopant types, concentrations, and orientations produced in solutions of HF:HNO3:H2O. Luminescence is also observed in stain films produced in solutions of NaNO2 in HF, but not in stain films produced in solutions of CrO3 in HF. The luminescence spectra are similar to those reported recently for porous Si films produced by anodic etching in HF solutions. However, stain films are much easier to produce, requiring no special equipment.

Objective: To determine the reliability and validity of the flashlight test and van Herick's test in detecting occludable anterior chamber angles.Methods:The flashlight test, van Herick's test and gonioscopy were performed independently by two observers on 96 consecutive new patients in our outpatient clinic. lnterobserver agreement was determined using the weighted Kappa statistic. Using the glaucoma specialist's assessment of occludability of the angle (assessed by gonioscopy) as a gold standard, the sensitivities and specificities of the two tests were calculated.Results: All three tests showed good agreement (Kappa more than 0.75). The sensitivity and specificity of the flashlight test were 45.5% and 82.7% respectively. For the van Herick's test they were 61.9% and 89.3%. Conclusion:The flashlight test and van Herick's test are of limited use as screening tests for occludable angles.

We report a unique, cooperative mechanism that involves the interplay of Ge, Si, and Oxygen interstitials enabling an unusual Ostwald ripening and migration behavior of Ge nanocrystallites and quantum dots (QDs) embedded within a SiO 2 matrix. In the presence of high Si interstitial fluxes with no supply of oxygen interstitials, the oxide surrounding the Ge QDs is decomposed by the Si interstitials, creating the volatile SiO reaction product and hence voids that enable the Ge QDs to grow by Ostwald ripening. When both Si and Oxygen interstitials are present in high concentrations, the Ostwald ripened Ge QD is further able to migrate towards the source of the Si interstitials. The QD movement occurs by virtue of the fact that the SiO created in front of the QD combines with O interstitials to regenerate SiO 2 behind the Ge QD on its migration path. Thus, SiO influences the migration and Ostwald ripening behavior of the Ge QDs via a unique "Destruction-Construction" mechanism. V C 2014 AIP Publishing LLC. [http://dx.

We have developed a new nanochannel fabrication technique using chemical-mechanical polishing (CMP) and thermal oxidation. With this technique, it is possible to control the width, length, and depth of the nanochannels without the need for nanolithography. The use of sacrificial SiO 2 layers allows the fabrication of centimeter-long nanochannels. In addition, the fabrication process is CMOS compatible. We have successfully fabricated an array of extremely long and narrow nanochannels (i.e., 10 mm long, 25 nm wide, and 100 nm deep) with smooth inner surfaces.

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