Electronics and Telecommunications Research Institute

Lg Chem, Ltd

Woo Ram Lee

Byoung Whi Kim

Seung Hyun Cho

Jie Hyun Lee

Mahn Yong Park

Geon Jeong

Chul Young Kim

Sang Ho Kim

Young Soo Lim

Dong Hoon Lee

Hyun Jun Lee

Yun Chur Chung

Ju Young Kim

Sang Soon Choi

Na Ri Park

Jun Ho Eom

Dong Jin Kim

Hyun Uk Kim

Jae Dong Park

Hwa Seok Chae

Woo Hyun Kim

Eui Seung Son

Jae Geun Kim

Tae Moon Park

Dae Chul Jung

Jang Won Chae

Dong Ryoung Kang

Na Ri Kim

A positive electrode material, a positive electrode including the same, and a lithium secondary battery including the same are disclosed herein. In some embodiments, a positive electrode material includes a first positive electrode active material having a larger average particle diameter than a second positive electrode active material, wherein the first positive electrode active material and the second positive electrode active material are each independently a lithium transition metal oxide having a molar ratio of nickel of 80 mol % or more relative to the total molar amount of transition metals in the lithium transition metal oxide, and the positive electrode material satisfies Equation (1):0<{()/}×100≤10  Equation (1):wherein, in Equation (1), A denotes a particle strength of the first positive electrode active material, and B denotes a particle strength of the second positive electrode active material.

Positive electrode material for lithium secondary battery, and positive electrode and lithium secondary battery which include the same

Provided is a method of manufacturing a positive electrode active material, which includes: (A) preparing a positive electrode active material precursor which includes a core portion including randomly aggregated primary particles and a shell portion surrounding the core portion and formed of primary particles oriented in a direction from a particle center to the outside and in which a ratio of a crystal grain size in the (100) plane to a crystal grain size in the (001) plane of the primary particles forming the shell portion is 3 or more; and (B) mixing the positive electrode active material precursor with a lithium-containing raw material and firing the mixture, wherein the lithium transition metal oxide has an average particle diameter (D) that is 0.01% to 20% reduced as compared to an average particle diameter (D) of the positive electrode active material precursor.

Method of manufacturing positive electrode active material

The present invention relates to a stripper composition for removing photoresists which comprises: a chained amine compound having a weight average molecular weight of more than 95 g/mol; a chained amine compound having a weight average molecular weight of not more than 90 g/mol; a cyclic amine compound; an amide-based compound in which a linear or branched alkyl group having 1-5 carbon atoms is mono- or di-substituted with nitrogen; and a polar organic solvent, wherein the weight ratio of the chained amine compound having a weight average molecular weight of more than 95 g/mol to the chained amine compound having the weight average molecular weight of not more than 90 g/mol is 1:1 to 1:10, and a method for stripping a photoresist using the same.

Stripper composition for removing photoresists and method for stripping photoresists using the same

Disclosed herein are core-shell type nanoparticles comprising nanoparticle cores made of a metal or semiconductor, and shells made of crystalline metal oxide formed on the surfaces of the nanoparticle cores, as well as a preparation method thereof. According to the disclosed invention, the core-shell nanoparticles, consisting of metallic or semiconductor cores and crystalline metal oxide shells, can be prepared by epitaxially growing metal oxide on the surfaces of the metallic or semiconductor nanoparticle cores. By virtue of the crystalline metal oxide shells, the core nanoparticle made of metal or semiconductor can ensure excellent chemical and mechanical stability, and the core-shell nanoparticles can show new properties resulting from the interaction between the metal cores and the metal oxide crystal shells.

Core-shell type nanoparticles comprising crystalline metal-oxide shell and method for preparing the same

Provided is an athermal external cavity laser (ECL), whose output optical power and output wavelength can be kept regular irrespective of temperature changes without using additional temperature controlling components. The ECL comprises: a semiconductor amplifier; an optical fiber comprising a core in which a Bragg grating is formed and a cladding surrounding the core; and a thermosetting polymer that fixes the optical fiber to a ferrule and has a negative thermooptical coefficient, wherein the thickness of the cladding surrounding the core in which the Bragg grating is formed is smaller than the portion of the cladding surrounding the portion of the core where the Bragg grating is not formed, and the thermosetting polymer the negative thermooptical coefficient surrounds the cladding. The ECL does not need additional temperature controlling components and thus can be manufactured compact and at low cost, and thus can be used as a light source of a dense wavelength division multiplexing (DWDM) system in designing economical WDM passive optical networks (PON).

Athermal external cavity laser

Provided are an apparatus and method for tracking a wavelength in a passive optical subscriber network in which a central base station and at least one subscriber terminal are connected via a remote node. The apparatus includes a first wavelength aligning unit multiplexing and aligning wavelengths of optical signals from a plurality of single-mode optical sources of the central base station; a second wavelength aligning unit multiplexing and aligning wavelengths of optical signals transmitted to the remote node from a plurality of single-mode optical sources of the subscriber terminal; and a third wavelength aligning unit demultiplexing and aligning wavelengths of optical signals from the second wavelength aligning unit, the third wavelength aligning unit being included in the central base station. Accordingly, when the wavelengths of passbands of a multiplexer/demultiplexer (MUX/DEMUX) of a remote station change due to a change in the ambient temperature, wavelength tracking is performed by making aligned the wavelengths of optical sources of a central base station, a multiplexer/demultiplexer, and subscriber terminals, thereby minimizing optical channel loss and enabling reliable management of WDM-PON.

Wavelength tracking apparatus and method in WDM-PON system

Core-shell type nanoparticles comprising metal cores and crystalline shells of metal oxide or metalloid oxide

A reflective semiconductor optical amplifier (RSOA) and an operating system based on a downstream optical signal reuse method with feed-forward current injection are provided. The RSOA has two active regions and includes a reflecting plane that reflects an input optical signal; and an optical amplifying semiconductor including a rear portion, which is positioned at a side of the reflecting plane and to which a signal having polarity opposite to that of the input optical signal is injected, and a front portion, which is positioned at a side opposite to the side of the rear portion facing the reflecting plane and which the input optical signal is passed though and a signal used to modulate a reflected input optical signal from the reflecting plane to an output optical signal is injected into.

Feed-forward current injection circuits and semiconductor optical amplifier structures for downstream optical signal reuse method

A method for fabricating a laser includes preparing an optical fiber including the optical fiber Bragg grating formed at a region thereof, and a ferrule provided with a cylindrical free space penetrating both ends thereof; applying a first thermal epoxy resin to a partial region of the outer cylindrical surface of the other region of the optical fiber, at which the optical fiber Bragg grating is not formed; inserting the optical fiber into the ferrule so that the region of the optical fiber at which the optical fiber Bragg grating is formed and the region of the optical fiber to which the first thermal epoxy resin is applied are located in the cylindrical free space of the ferrule; fixing the optical fiber to the ferrule by curing the first thermal epoxy resin; and optically coupling one end of the optical fiber, fixed to the ferrule, and a light source.

Method for fabricating laser diode having optical fiber Bragg grating as front mirror of external resonator and laser diode fabricated thereby

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Daejeon, South Korea

Woo Ram Lee