Abstract: A light-emitting device includes a semiconductor epitaxial structure that has a first surface and a second surface, and that includes a first semiconductor layer, an active layer, and a second semiconductor layer. The active layer includes a quantum well structure having multiple periodic units, each including a well layer and a barrier layer greater in bandgap than the well layer. The bandgap of the barrier layer of at least one of the periodic units proximate to the first surface is smaller than that proximate to the second surface, and a thickness of the well layer of at least one of the periodic units proximate to the first surface is greater than that proximate to the second surface. In some embodiments, a bandgap of a second spacing layer disposed between the active and second semiconductor layers increases in a direction from the first surface to the second surface.

Abstract: A light-emitting device includes a semiconductor epitaxial structure that has a first surface and a second surface, and that includes a first semiconductor layer, an active layer, and a second semiconductor layer. The active layer includes a quantum well structure having multiple periodic units, each including a well layer and a barrier layer greater in bandgap than the well layer. The bandgap of the barrier layer of at least one of the periodic units proximate to the first surface is smaller than that proximate to the second surface, and a thickness of the well layer of at least one of the periodic units proximate to the first surface is greater than that proximate to the second surface. In some embodiments, a bandgap of a second spacing layer disposed between the active and second semiconductor layers increases in a direction from the first surface to the second surface.

Abstract: A light emitting diode has a light emitting region including a multiple quantum well structure, including a first protection layer, a first intermediate layer over the first protection layer, a quantum barrier layer over the first intermediate layer, a second intermediate layer over the well layer, a second protection layer over the second intermediate layer, and a quantum barrier layer over the second protection layer.

Abstract: A nitride light-emitting diode includes a substrate, an n-type nitride layer, a light-emitting layer, a p-type nitride layer, a p+ layer, an AlInN layer, an n+ layer, and an ITO transparent electrode. A tunneling structure with an AlInN intermediate layer is adopted as the contact layer, which generates polarization charges at the tunneling junction interface and maintains effective width of the depletion region, thereby increasing tunneling probability of holes and reducing contact resistances.

Abstract: A light emitting diode has a light emitting region including a multiple quantum well structure, including a first protection layer, a first intermediate layer over the first protection layer, a quantum barrier layer over the first intermediate layer, a second intermediate layer over the well layer, a second protection layer over the second intermediate layer, and a quantum barrier layer over the second protection layer.

Abstract: A nitride light-emitting diode includes a substrate, an n-type nitride layer, a light-emitting layer, a p-type nitride layer, a p+ layer, an AlInN layer, an n+ layer, and an ITO transparent electrode. A tunneling structure with an AlInN intermediate layer is adopted as the contact layer, which generates polarization charges at the tunneling junction interface and maintains effective width of the depletion region, thereby increasing tunneling probability of holes and reducing contact resistances.

Abstract: A Magnolia officinalis Rehd. et Wils. extract feed additive and a preparation method thereof are provided. The Magnolia officinalis Rehd. et Wils. extract feed additive takes a Magnolia officinalis Rehd. et Wils. extract and a carrier as raw materials. The Magnolia officinalis Rehd. et Wils. extract is prepared by the ultrasonic auxiliary water extraction. The preparation method of the present invention has less raw material waste, high activity component content in the extract and acquisition rate of the extractum, which facilitates improving the effect efficiency and reducing production cost. The Magnolia officinalis Rehd. et Wils. extract feed additive as a natural plant feed additive has a better rehabilitating effect on gastric ulcer and anti-cancer of livestock and greatly reduces the economic loss due to gastric ulcer.