Samsung Electronics Co., Ltd.

Samsung Display Co., Ltd.

Intron Biotechnology, Inc.

Taek Hoon Kim

Shin Ae Jun

Eun Joo Jang

Jongmin Lee

Soo Kyung Kwon

Won Joo Lee

Tae Gon Kim

Nayoun Won

Hyeyeon Yang

Mi Hye Lim

Min Sik Kim

Ngoc Phan Vu

Kwang Yeol Lee

Jin A Kim

Young Seok Park

Quantum dots and a composite and a display device including the quantum dots. The quantum dots comprise a semiconductor nanocrystal core comprising indium and phosphorous, and optionally zinc, a semiconductor nanocrystal shell disposed on the semiconductor nanocrystal core, the first semiconductor nanocrystal shell comprising zinc, selenium, and sulfur, wherein the quantum dots are configured to exhibit a maximum photoluminescence peak in a green light wavelength region, and in an ultraviolet-visible (UV-Vis) absorption spectrum of the quantum dots, a ratio A/A, of an absorption value at 450 nm to an absorption value at a first excitation peak is greater than or equal to about 0.7, and a valley depth (VD) defined by the following equation is greater than or equal to about 0.4:(Abs&#x2212;Abs)/Abs=VD

Quantum dots, a composition or composite including the same, and an electronic device including the same

A nanocrystal including a core including a Group III element and a Group V element, and a monolayer shell on the surface of the core, the shell including a compound of the formula ZnSeS, wherein 0&#x2264;x&#x2264;1, and wherein an average mole ratio of Se:S in the monolayer shell ranges from about 2:1 to about 20:1.

Semiconductor nanocrystal, and method of preparing the same

A quantum dot, and a composite and a display device including the quantum dot. The quantum dot comprises a semiconductor nanocrystal core comprising indium and phosphorous, a semiconductor nanocrystal shell disposed on the semiconductor nanocrystal core, the first semiconductor nanocrystal shell comprising zinc, selenium, and sulfur, wherein the quantum dot does not comprise cadmium wherein the quantum dot has a maximum photoluminescence peak in a green light wavelength region, and wherein in an ultraviolet-visible (UV-Vis) absorption spectrum of the quantum dot, a ratio A/A, of an absorption value at 450 nm to an absorption value at a first excitation peak is greater than or equal to about 0.7, and a valley depth (VD) defined by the following equation is greater than or equal to about 0.4:()/=VD

The present invention relates to a magnetic resonance imaging (MRI) contrast agent, particularly an MRI contrast agent derived from nanoparticle that is porous first metal-doped second metal oxide nanoparticle with a central cavity, and a method for producing the same. The MEI contrast agent made in accordance with the present invention can be used not only as a drug-delivery agent for therapy but also as an MRI contrast agent for diagnosis.

Metal oxide nanoparticle-based magnetic resonance imaging contrast agent with a central cavity

The present invention relates to a magnetic resonance imaging (MRI) contrast agent, particularly a metal oxide nanoparticle-based T1-T2 dual-mode MRI contrast agent that can be used not only as a T1 MRI contrast agent but also as a T2 MRI contrast agent, and a method for producing the same. The metal oxide nanoparticle-based T1-T2 dual-mode MRI contrast agent can provide more accurate and detailed information associated with disease than single MRI contrast agent by the beneficial contrast effects in both T1 imaging with high tissue resolution and T2 imaging with high feasibility on detection of a lesion.

Metal oxide nanoparticle-based T1-T2 dual-mode magnetic resonance imaging contrast agent

A quantum dot including a seed including a first semiconductor nanocrystal including a first Group II-VI compound, a quantum well surrounding the seed, the quantum well including a second semiconductor nanocrystal including a Group IIIA metal except aluminum and a Group V element, and a shell disposed on the quantum well, the shell including a third semiconductor nanocrystal including a second Group II-VI compound, wherein the quantum dot does not include cadmium, an energy bandgap of the second semiconductor nanocrystal is smaller than an energy bandgap of the first semiconductor nanocrystal and an energy bandgap of the third semiconductor nanocrystal, and an ultraviolet-visible (UV-Vis) absorption spectrum curve of the quantum dot does not have an inflection point within a wavelength range of about 450 nanometers (nm) to about 600 nm, and a quantum dot composite and a device including the same.

Quantum dots, compositions and composites including the same, and electronic device including the same

The number and type of quantum wells in a multi-layer gain structure of an external cavity surface emitting laser (VECSEL) are controlled to provide output light of more than one coherent wavelength. The number and type of layers in a multiplayer mirror provides a dual wavelength reflector.

External cavity dual wavelength laser system

A long wavelength vertical cavity surface emitting laser (VCSEL) with a monolithically-grown photodetector is provided. The photodetector is installed in a middle portion of or on a bottom surface of a lower distributed Bragg reflector of the long wavelength VCSEL. The photodetector is integrated with the long wavelength VCSEL. A substrate on which the long wavelength VCSEL and the photodetector are crystal-grown does not absorb a laser beam emitted from the long wavelength VCSEL. Thus, the laser beam heading toward the substrate is accurately detected, and the gain of the laser beam is effectively controlled.

Long wavelength vertical cavity surface emitting laser with monolithically grown photodetector

A wavelength tunable VCSEL is provided. The wavelength tunable VCSEL includes a current constricting layer which is formed on a lower distributed Bragg reflector, upper and lower electrodes for laser oscillation, and additional electrodes which are formed on a predetermined region of an upper distributed Bragg reflector from which light is emitted so as to vary a width of an effective resonance region. Compared to an existing VCSEL, the wavelength tunable VCSEL can rapidly change a wavelength of emitted light and prevent the deterioration of gain characteristics of laser oscillation due to variations in the width of the effective resonance region according to variations in a temperature. As a result, a wavelength tunable region of emitted laser can be increased.

Wavelength tunable VCSEL

A surface-emitting light-emitting diode having increased light emission is provided. The surface-emitting light-emitting diode includes a substrate, a light generating layer comprising an active layer for generating light, and an upper clad layer and a lower clad layer formed on and below the active layer, respectively, a lower contact layer formed between the light generating layer and the substrate, a buffer layer formed between the lower contact layer and the substrate, a lower ohmic metal layer which ohmically contacts one side of the lower contact layer, an upper contact layer formed on the light generating layer and having a substantially sinusoidal uneven surface portion; and a light transmissive upper ohmic metal layer formed on the upper contact layer, in which the active layer is composed of GaN or AlN, the lower contact layer is composed of doped n-GaN, the upper contact layer is composed doped p-GaN, and the substantially sinusoidal uneven surface portion increases the contact area between the upper contact layer and light transmissive upper ohmic metal layer for reducing the contact resistance therebetween. Therefore, ohmic contact resistance and operating current are reduced, so that durability is improved due to the reduction of hear generated in the device. Also, light is condensed by the substantially sinusoidal uneven surface portion and thus the amount of light which is totally reflected internally is reduced. Accordingly, no additional package device is required and external quantum efficiency is increased.

Growing community of inventors

Hwaseong-si, South Korea

Taek Hoon Kim