A population of bright and stable nanocrystals is provided. The nanocrystals include a semiconductor core and a thick semiconductor shell and can exhibit high extinction coefficients, high quantum yields, and limited or no detectable blinking.

A device including one or more layers with lateral regions configured to facilitate the transmission of radiation through the layer and lateral regions configured to facilitate current flow through the layer is provided. The layer can comprise a short period superlattice, which includes barriers alternating with wells. In this case, the barriers can include both transparent regions, which are configured to reduce an amount of radiation that is absorbed in the layer, and higher conductive regions, which are configured to keep the voltage drop across the layer within a desired range.

The invention relates to an optoelectronic light-emitting device (1), including: at least one light-emitting diode (40) having an emitting surface (44) adapted to emit so-called excitation luminous radiation; and a photoluminescent material (31) that coats the emitting surface (44), the photoluminescent material containing photoluminescent particles adapted to convert said excitation luminous radiation through the emitting surface (44) at least in part into so-called photoluminescence luminous radiation.

The optoelectronic device includes at least one photodiode (50) adjacent the light-emitting diode (40) having a receiving surface (54) coated by the photoluminescent material (31) and adapted to detect at least part of the excitation radiation and/or the photoluminescence radiation coming from the photoluminescent material (31) through the receiving surface.

Methods of controlling stress in GaN films deposited on silicon and silicon carbide substrates and the films produced therefrom are disclosed. A typical method comprises providing a substrate and depositing a graded gallium nitride layer on the substrate having a varying composition of a substantially continuous grade from an initial composition to a final composition formed from a supply of at least one precursor in a growth chamber without any interruption in the supply. A typical semiconductor film comprises a substrate and a graded gallium nitride layer deposited on the substrate having a varying composition of a substantially continuous grade from an initial composition to a final composition formed from a supply of at least one precursor in a growth chamber without any interruption in the supply.

Optoelectric devices that comprise a semiconductor superlattice heterostructure. One or more individual layers within the semiconductor superlattice heterostructure can further comprise layers of differing thicknesses. In at least one embodiment, an optoelectric device with specially engineered layers can generate an output wavelength of between 3 m to 15 m at output power levels of 0.01 mW to 100 mW.

Provided is a method that can manufacture a light-emitting device in which quantum dot is used and which has a high luminous efficiency. A light-emitting device (1) is manufactured that includes: a cell (10) including first and second glass plates (11, 12) facing and spaced apart from each other; and quantum dot (17) encapsulated in the cell (10). Prior to the encapsulation of the quantum dot (17), a reduction step of reducing moisture adsorbed on the inside walls of the cell (10) is performed.

In various embodiments, light-emitting devices incorporate smooth contact layers and polarization doping (i.e., underlying layers substantially free of dopant impurities) and exhibit high photon extraction efficiencies.

A display may be provided with light sources. The light sources may include light emitting diodes. The light sources may have packages formed from package bodies to which the light-emitting diodes are mounted. Layers such as quantum dot layers, light-scattering layers, spacer layers, and diffusion barrier layers may be formed over the package bodies and light-emitting diodes. Quantum dots of different colors may be stacked on top of each other. A getter may be incorporated into one or more of the layers to getter oxygen and water. Quantum dots may be formed from semiconductor layers that are doped with n-type and p-type dopant to adjust the locations of their conduction and valance bands and thereby enhanced quantum dot performance.

A quantum dot includes a core-shell structure including a core including a first semiconductor nanocrystal and a shell disposed on the core, and including a material at least two different halogens, and the quantum dot does not include cadmium.

A heterostructure for use in fabricating an optoelectronic device is provided. The heterostructure includes a layer, such as an n-type contact or cladding layer, that includes thin sub-layers inserted therein. The thin sub-layers can be spaced throughout the layer and separated by intervening sub-layers fabricated of the material for the layer. The thin sub-layers can have a distinct composition from the intervening sub-layers, which alters stresses present during growth of the heterostructure.