Abstract: Sulfonated polymers are made by the direct polymerization of a sulfonated monomer to form the sulfonated polymers. The types of sulfonated polymers may include polysulfones or polyimides. The sulfonated polymers can be formed into membranes that may be used in proton exchange membrane fuel cells or as ion exchange membranes. The membranes formed from the sulfonated polymers exhibit improved properties over that of Nafion®. A heteropoly acid may be added to the sulfonated polymer to form a nanocomposite membrane in which the heteropoly acid is highly dispersed. The addition of a heteropoly acid to the sulfonated polymer increases the thermal stability of the membrane, enhances the conductivity above 100° C., and reduces the water uptake of the membrane.

Abstract: A nitride semiconductor light emitting device includes a light emitting structure having n-type and p-type nitride semiconductor layers and an active layer formed therebetween. N-type and p-type electrodes are electrically connected to the n-type and p-type nitride semiconductors, respectively. An n-type ohmic contact layer is formed between the n-type nitride semiconductor layer and the n-type electrode and has a first layer of a material In and a second layer formed on the first layer and of a material containing W. The nitride semiconductor light emitting device has thermal stability and excellent electrical characteristics without heat treatment.

Abstract: A method of preparing advanced membrane electrode assemblies (MEA) for use in fuel cells. A base polymer is selected for a base membrane. An electrode composition is selected to optimize properties exhibited by the membrane electrode assembly based on the selection of the base polymer. A property-tuning coating layer composition is selected based on compatibility with the base polymer and the electrode composition. A solvent is selected based on the interaction of the solvent with the base polymer and the property-tuning coating layer composition. The MEA is assembled by preparing the base membrane and then applying the property-tuning coating layer to form a composite membrane. Finally, a catalyst is applied to the composite membrane.

Abstract: An electrochemical cell assembly that is expected to prevent or at least minimize electrode contamination includes one or more getters that trap a component or components leached from a first electrode and prevents or at least minimizes them from contaminating a second electrode.

Abstract: An ionomer may be used as a binder for a catalyst to prepare an anode for a solid alkaline fuel cell. The ionomer is a reaction product of a guanidine and a perfluorosulfonic acid polymer.

Abstract: Compositions, and methods of making thereof, comprising from about 1% to about 5% of a perfluorinated sulfonic acid ionomer or a hydrocarbon-based ionomer; and from about 95% to about 99% of a solvent, said solvent consisting essentially of a polyol; wherein said composition is substantially free of water and wherein said ionomer is uniformly dispersed in said solvent.

Abstract: A method of preparing advanced membrane electrode assemblies (MEA) for use in fuel cells. A base polymer is selected for a base membrane. An electrode composition is selected to optimize properties exhibited by the membrane electrode assembly based on the selection of the base polymer. A property-tuning coating layer composition is selected based on compatibility with the base polymer and the electrode composition. A solvent is selected based on the interaction of the solvent with the base polymer and the property-tuning coating layer composition. The MEA is assembled by preparing the base membrane and then applying the property-tuning coating layer to form a composite membrane. Finally, a catalyst is applied to the composite membrane.

Abstract: A wireless communication system for geographically controlling a communication area includes an access point for communicating with a terminal in a first area, and a jammer for generating noise for intercepting communication between the access point and a terminal in a second area. A jamming boundary for dividing an area in which the terminal can communicate with the access point and an area in which the terminal cannot communicate with the access point in an area in which the first area and the second area are overlapped is formed, and the jamming boundary is formed by a ratio between power of a signal transmitted to the terminal by the access point and power of a signal of the noise.

Abstract: There is provided a semiconductor light emitting device including a conductive substrate, a first electrode layer, an insulating layer, a second electrode layer, a second semiconductor layer, an active layer, and a first semiconductor layer that are sequentially stacked. The contact area between the first electrode layer and the first semiconductor layer is 3% to 13% of the total area of the semiconductor light emitting device, and thus high luminous efficiency is achieved.

Abstract: There is provided a method of forming a pattern on a group III nitride semiconductor substrate. A method of forming a pattern on a group III nitride semiconductor substrate according to an aspect of the invention may include: irradiating a laser beam onto at least one first region for preventing etching in a group III nitride semiconductor substrate; and etching at least one second region exclusive of the first region using the first region irradiated with the laser beam as a mask.

Abstract: The present invention relates to a vertical/horizontal light-emitting diode for a semiconductor.

Abstract: Provided are a semiconductor light emitting device and a method for fabricating the same. The semiconductor light emitting device includes a light emitting structure and a pattern. The light emitting structure includes a first-conductivity-type semiconductor layer, an active layer, and a second-conductivity-type semiconductor layer. The pattern is formed on at least one light emitting surface among the surfaces of the light emitting structure. The pattern has a plurality of convex or concave parts that are similar in shape. The light emitting surface with the pattern formed thereon has a plurality of virtual reference regions that are equal in size and are arranged in a regular manner. The convex or concave part is disposed in the reference regions such that a part of the edge thereof is in contact with the outline of one of the plurality of virtual reference regions.

Abstract: Solid anion exchange polymer electrolytes include chemical compounds comprising a polymer backbone with side chains that include guanidinium cations.

Abstract: Compositions, and methods of making thereof, comprising from about 1% to about 5% of a perfluorinated sulfonic acid ionomer or a hydrocarbon-based ionomer; and from about 95% to about 99% of a solvent, said solvent consisting essentially of a polyol; wherein said composition is substantially free of water and wherein said ionomer is uniformly dispersed in said solvent.

Abstract: Sulfonated polymers are made by the direct polymerization of a sulfonated monomer to form the sulfonated polymers. The types of sulfonated polymers may include polysulfones or polyimides. The sulfonated polymers can be formed into membranes that may be used in proton exchange membrane fuel cells or as ion exchange membranes. The membranes formed from the sulfonated polymers exhibit improved properties over that of Nafion®. A heteropoly acid may be added to the sulfonated polymer to form a nanocomposite membrane in which the heteropoly acid is highly dispersed. The addition of a heteropoly acid to the sulfonated polymer increases the thermal stability of the membrane, enhances the conductivity above 100° C., and reduces the water uptake of the membrane.

Abstract: The present invention provides a semiconductor light emitting device including a conductive substrate, a first electrode layer, an insulating layer, a second electrode layer, a second semiconductor layer, an active layer, and a first semiconductor layer which are sequentially stacked, wherein an area where the first electrode layer and the first semiconductor layer are in contact with each other is 3 to 13% of an area of the semiconductor light emitting device.

Abstract: Compositions, and methods of making thereof, comprising from about 1% to about 5% of a perfluorinated sulfonic acid ionomer or a hydrocarbon-based ionomer; and from about 95% to about 99% of a solvent, said solvent consisting essentially of a polyol; wherein said composition is substantially free of water and wherein said ionomer is uniformly dispersed in said solvent.

Abstract: Disclosed are a semiconductor light emitting device, which can improve characteristics of the semiconductor light emitting device such as a forward voltage characteristic and a turn-on voltage characteristic, increase light emission efficiency by lowering an input voltage, and increase reliability of the semiconductor light emitting device by a low-voltage operation, and a method of manufacturing the same. The semiconductor light emitting device includes: an n-type GaN semiconductor layer; an active layer formed on a gallium face of the n-type GaN semiconductor layer; a p-type semiconductor layer formed on the active layer; and an n-type electrode formed on a nitrogen face of the n-type GaN semiconductor layer and including a lanthanum (La)-nickel (Ni) alloy.

Abstract: A wireless communication system for geographically controlling a communication area includes an access point for communicating with a terminal in a first area, and a jammer for generating noise for intercepting communication between the access point and a terminal in a second area. A jamming boundary for dividing an area in which the terminal can communicate with the access point and an area in which the terminal cannot communicate with the access point in an area in which the first area and the second area are overlapped is formed, and the jamming boundary is formed by a ratio between power of a signal transmitted to the terminal by the access point and power of a signal of the noise.

Abstract: There is provided a nitride semiconductor light emitting device including: a light emitting structure including n-type and p-type nitride semiconductor layers and an active layer disposed therebetween; n- and p-electrodes electrically connected to the n-type and p-type nitride semiconductor layers, respectively; and an n-type ohmic contact layer disposed between the n-type nitride semiconductor layer and the n-electrode and including a first layer and a second layer, the first layer formed of an In-containing material, and the second layer disposed on the first layer and formed of a transparent conductive oxide. The nitride semiconductor light emitting device including the n-electrode exhibits high light transmittance and superior electrical characteristics. Further, the nitride semiconductor light emitting device can be manufactured by an optimal method to ensure superb optical and electrical characteristics.