An epitaxial structure includes a quantum well structure, a first type semiconductor layer, and a second type semiconductor layer. The quantum well structure has an upper surface and a lower surface opposite to each other and includes at least one quantum well layer and at least one quantum barrier layer stacked alternately. The quantum well layer includes at least one patterned layer, and the patterned layer includes multiple geometric patterns. The first type semiconductor layer is disposed on the lower surface of the quantum well structure. The second type semiconductor layer is disposed on the upper surface of the quantum well structure.

A light-emitting diode includes a material structure of barrier in the light-emitting well region to improve restriction capacity of electron holes, improving light-emitting efficiency of the LED chip under high temperature. The LED structure includes a Type I semiconductor layer, a Type II semiconductor layer and an active layer between the both, wherein, the active layer is a multi-quantum well structure alternatively composed of well layers and barrier layers, in which, the first barrier layer is a first AlGaN gradient layer in which aluminum components gradually increase in the direction from the Type I semiconductor layer to the quantum well, and the barrier layer at the middle of well layers is an AlGaN/GaN/AlGaN multi-layer barrier layer, and the last barrier layer is a second AlGaN gradient layer in which aluminum components gradually decrease in the direction from the quantum well to the Type II semiconductor layer.

A plant cultivation light source includes a plurality of light sources configured to be turned on or turned off depending on a selected plant and a growth stage of the selected plant, and a controller. The controller is operable to turn on the light sources during a light period such that the light sources are operable to emit a light having a spectrum with a plurality of peaks to the selected plant. The light period including a first period and a second period and the first period preceding or following the second period. The controller is operable to adjust the spectrum of the light to alternate the first period and the second period during the light period.

A light-emitting structure includes an n-type layer, an active layer, and a p-type layer. The active layer has N quantum well structure periods, each of the N quantum-well structure periods has a well layer and at least one barrier layer. The N quantum-well structure periods include a first light-emitting section and a second light-emitting section. The first light-emitting section is closer to the n-type layer than the second light-emitting section. A method for producing the light-emitting structure, and a light-emitting device that has the light-emitting structure are also disclosed.

Provided are nanorod light emitting diodes (LEDs), display apparatuses, and manufacturing methods thereof. The nanorod LED includes a first-type semiconductor layer including a body and a pyramidal structure continuously provided from the body, a nitride light emitting layer provided on the pyramidal structure, and a second-type semiconductor layer provided in the nitride light emitting layer.

A method includes: introducing a gas including gallium, an ammonia gas, and a gas including a p-type impurity to a reactor and forming a first p-type nitride semiconductor layer on a first light-emitting layer in a state in which the reactor has been heated to a first temperature; lowering a temperature of the reactor from the first temperature to a second temperature; introducing an ammonia gas with a first flow rate to the reactor and increasing the temperature of the reactor from the second temperature to a third temperature; and introducing a gas including gallium, an ammonia gas with a second flow rate, and a gas including an n-type impurity to the reactor, and forming a second n-type nitride semiconductor layer on the first p-type nitride semiconductor layer in a state in which the reactor has been heated to the third temperature.

A method for manufacturing a nitride semiconductor light-emitting element includes growing a p-type cladding layer with an average Al composition ratio in a thickness direction of not less than 70%, and growing a p-type contact layer with an Al composition ratio of not more than 10%. A flow rate ratio F.sub.p/F.sub.III is a p/III ratio and a flow rate ratio F.sub.V/F.sub.III is a V/III ratio. The p-type cladding layer is grown in the growing the p-type cladding layer at a growth rate of not more than 2.5 nm/min, a p/III ratio of not less than 0.0002 and not more than 0.0400 and a VIII ratio of not more than 7000. The p-type contact layer is grown in the growing the p-type contact layer at a growth rate of not more than 3.3 nm/min, a p/III ratio of not less than 0.0200 and a V/III ratio of not less than 10000.

An epitaxial structure includes an n-type layer, a p-type layer, an active layer, and a current spreading layer. The active and current spreading layers respectively have first and third concentration profiles of indium which respectively include first and third characteristic peaks. A heavily doped layer formed between the active and current spreading layers has a second concentration profile of silicon with a second characteristic peak. A ratio of a first minimum horizontal distance between peak tops of first and third characteristic peaks, to a second minimum horizontal distance between peak tops of second and third characteristic peaks, is less than one seventh.

A light-emitting diode may include: a first n-doped semiconductor portion; a second p-doped semiconductor portion; an active zone disposed between the first and second portions and including at least one emitting semiconductor portion; a layer that is electrically conductive and optically transparent to at least one wavelength of the UV range configured to be emitted from the emitting portion, the layer being such that the second portion is disposed between the layer and the active zone. The semiconductors of the first portion and of the emitting portion may include compounds including nitrogen atoms as well as atoms of aluminum and/or of gallium. The semiconductor of the second portion may include Al.sub.X2Ga.sub.(1-X2-Y2)In.sub.Y2N that is p-doped with magnesium atoms, wherein X2>0, Y2>0, and X2+Y2<1, and in which the atomic concentration of magnesium is greater than 10.sup.17 at/cm.sup.3. The electrically conductive layer may include doped diamond.

A semiconductor device, includes: a first conductive type semiconductor region including a first semiconductor structure, wherein the first semiconductor structure includes one or more pairs of stack, the one or more pairs of stack respectively includes a first layer and a second layer, the first layer includes Al.sub.xGa.sub.1-xN, the second layer includes Al.sub.yGa.sub.1-yN, wherein 0≤x<1, 0<y<1, x<y, wherein one of the one or more pairs of stack includes an interface region located between the first layer and the second layer adjacent to the first layer; a second conductive type semiconductor region located on the first conductive type semiconductor region; and an active region located between the first conductive type semiconductor region and the second conductive type semiconductor region; wherein the first semiconductor structure includes a first dopant having a first doping concentration with a peak value at the interface region.