Iuchi T.,Toyo University |
Toyoda Y.,Toyo University |
Seo T.,Japan Pionics Co.
Review of Scientific Instruments | Year: 2013
We studied the spectral and directional emissivities of silicon wafers using an optical polarization technique. Based on simulation and experimental results, we developed two radiation thermometry methods for silicon wafers: one is based on the polarized emissivity-invariant condition and the other is based on the relationship between the ratio of the p- and s-polarized radiance and the polarized emissivity. These methods can be performed at temperatures above 600 °C and over a wide wavelength range (0.9-4.8 μm), irrespective of the dielectric film thickness and the substrate resistivity, which depends on the dopant concentration. The temperature measurements were estimated to have expanded uncertainties (k = 2) of less than 5 °C. With a view to practically applying these methods, we investigated a method to reduce the intense background radiance produced by high-intensity heating lamps. We found that the background radiance can be greatly reduced by using a radiometer that is sensitive to wavelengths of 4.5 or 4.8 μm and suitable geometrical arrangements of a quartz plate. This opens up the possibility of using the two proposed radiation thermometry methods in practical applications. © 2013 American Institute of Physics. Source
Disposable, chemically activated pads which generate heat to keep the body, hands and feet warm in cold environments.
Japan Pionics Co. | Date: 2015-10-02
The present invention is to provide a method for refining hydrogen with a hydrogen refining device in which the inside of a cell is divided into a primary side space and a secondary side space by palladium alloy capillaries each having one end being closed and a tube sheet supporting the open end of the palladium alloy capillaries, in which impurity-containing hydrogen is introduced from the primary side space to allow hydrogen to permeate the palladium alloy capillaries so as to collect pure hydrogen from the secondary side space. The method for refining hydrogen has a capability of decreasing the removed amount of gas containing impurities and efficiently collecting pure hydrogen from the secondary side space. From hydrogen with 1000 ppm or less of impurities as raw material hydrogen, gas containing impurities that does not penetrate the palladium alloy capillaries is removed from the primary side space at the flow rate of 10% or less of the introduction flow rate of the raw material hydrogen. Furthermore, gas containing impurities that does not penetrate the palladium alloy capillaries is removed from the primary side space at a flow rate based on the content of impurities contained in raw material hydrogen.
Japan Pionics Co. | Date: 2015-12-17
The present invention provides a method of processing discharge gas containing ammonia, hydrogen, nitrogen, and an organic metal compound discharged from the production process of a gallium nitride compound semiconductor. The discharge gas is brought into contact with a cleaning agent prepared by impregnating an alkali metal compound with a metal oxide to remove the organic metal compound from the discharge gas. The discharge gas from which an organic metal compound is removed is brought into contact with an ammonia decomposition catalyst on heating to decompose the ammonia into nitrogen and hydrogen. The discharge gas in which ammonia is decomposed is brought into contact with palladium alloy membrane on heating to recover hydrogen that has penetrated through the palladium alloy membrane. After an organic metal compound is removed to liquefy the ammonia contained in the discharge gas as described above, a pressurization process and a cooling process is conducted by a heat pump to pressurize and cool the discharge gas from which an organic metal compound is removed to liquefy the ammonia contained in the discharge gas and separate the liquefied ammonia from hydrogen and nitrogen so as to recover the liquefied ammonia. The recovered hydrogen and ammonia are supplied to and reused in the production process of a gallium nitride compound semiconductor.
Iso K.,Japan Pionics Co. |
Takaki R.,Japan Pionics Co. |
Ishihama Y.,Japan Pionics Co. |
Inagawa T.,Tokyo Gas Co. |
Takahashi Y.,Japan Pionics Co.
Physica Status Solidi (A) Applications and Materials Science | Year: 2010
InGaN/GaN-based light emitting diodes (LEDs) can be grown by using metal organic chemical vapor deposition (MOCVD) to make eight, 3-inch diameter wafers with a thin, tapered reactor cell at atmospheric pressure. The reactor configuration was optimized for the purpose of improving the GaN growth rate and its in-plane distribution. The growth rate and the layer uniformity of GaN were improved when the reactor cell was narrowed down and tapered. The on-wafer deviation of the electroluminescence (EL) peak wavelength and power were 5 nm and within 4%, respectively, except at the edge. The full width at half maximum (FWHM) of EL spectrum for an LED grown at atmospheric pressure was consistently smaller than that of one grown at reduced pressure over the entire wavelength range. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source