Abstract: A deep ultraviolet LED with a design wavelength ?, including a reflecting electrode layer (Au), a metal layer (Ni), a p-GaN contact layer, a p-block layer made of a p-AlGaN layer, an i-guide layer made of an AlN layer, a multi-quantum well layer, an n-AlGaN contact layer, a u-AlGaN layer, an AlN template, and a sapphire substrate that are arranged in this order from a side opposite to the sapphire substrate, in which the thickness of the p-block layer is 52 to 56 nm, a two-dimensional reflecting photonic crystal periodic structure having a plurality of voids is provided in a region from the interface between the metal layer and the p-GaN contact layer to a position not beyond the interface between the p-GaN contact layer and the p-block layer in the thickness direction of the p-GaN contact layer, the distance from an end face of each of the voids in the direction of the sapphire substrate to the interface between the multi-quantum well layer and the i-guide layer satisfies ?/2n1Deff (where ? is the design wav

Abstract: A deep ultraviolet LED with a design wavelength ?, including a reflecting electrode layer (Au), a metal layer (Ni), a p-GaN contact layer, a p-block layer made of a p-AlGaN layer, an i-guide layer made of an AlN layer, a multi-quantum well layer, an n-AlGaN contact layer, a u-AlGaN layer, an AlN template, and a sapphire substrate that are arranged in this order from a side opposite to the sapphire substrate, in which the thickness of the p-block layer is 52 to 56 nm, a two-dimensional reflecting photonic crystal periodic structure having a plurality of voids is provided in a region from the interface between the metal layer and the p-GaN contact layer to a position not beyond the interface between the p-GaN contact layer and the p-block layer in the thickness direction of the p-GaN contact layer, the distance from an end face of each of the voids in the direction of the sapphire substrate to the interface between the multi-quantum well layer and the i-guide layer satisfies ?/2n1Deff (where ? is the design wav

Abstract: A UV LED element, which is an exemplary ultraviolet light-emitting diode according to the present invention, includes an n-type conductive layer, a light-emitting layer, an electron block layer, and a p-type contact layer, all of which are arranged in this order. Bandgap energy of the electron block layer satisfies Econtact?EEBL, where Econtact designates bandgap energy of the p-type contact layer and EEBL designates the bandgap energy of the electron block layer. The electric apparatus includes the UV LED element as a light source for emitting an ultraviolet ray.

Abstract: To fabricate a practically useful non-polar AlN buffer layer on a sapphire crystal plate and manufacture a UV light-emitting device on a non-polar crystal substrate by adopting the crystal substrate as an example, an embodiment of the present invention provides a crystal substrate 1D comprising an r-plane sapphire crystal plate 10 and an AlN buffer layer 20D of non-polar orientation. The AlN buffer layer comprises a surface protection layer 22 and a smoothing layer 26. The surface protection layer suppresses roughness increase on a surface of the AlN buffer layer, and the smoothing layer makes the surface of the AlN buffer layer a smoothed surface. Also provided is a crystal substrate 11 comprising an AlN buffer layer 20T to which a dislocation blocking layer 24 for reducing crystallographic defects is added between the surface protection layer 22 and the smoothing layer 26. In another embodiment a deep UV light-emitting device is provided.

Abstract: A UV LED element, which is an exemplary ultraviolet light-emitting diode according to the present invention, includes an n-type conductive layer, a light-emitting layer, an electron block layer, and a p-type contact layer, all of which are arranged in this order. Bandgap energy of the electron block layer satisfies Econtact?EEBL, where Econtact designates bandgap energy of the p-type contact layer and EEBL designates the bandgap energy of the electron block layer. The electric apparatus includes the UV LED element as a light source for emitting an ultraviolet ray.

Abstract: Provided is a deep ultraviolet LED with a design wavelength ?, including an Al reflecting electrode layer, an ultrathin metal layer, and a transparent p-AlGaN contact layer that are sequentially arranged from a side opposite to a substrate, and a photonic crystal periodic structure provided in the range of the thickness direction of the transparent p-AlGaN contact layer. The photonic crystal periodic structure has a photonic band gap.

Abstract: To fabricate a practically useful non-polar AlN buffer layer on a sapphire crystal plate and manufacture a UV light-emitting device on a non-polar crystal substrate by adopting the crystal substrate as an example, an embodiment of the present invention provides a crystal substrate 1D comprising an r-plane sapphire crystal plate 10 and an AlN buffer layer 20D of non-polar orientation. The AlN buffer layer comprises a surface protection layer 22 and a smoothing layer 26. The surface protection layer suppresses roughness increase on a surface of the AlN buffer layer, and the smoothing layer makes the surface of the AlN buffer layer a smoothed surface. Also provided is a crystal substrate 11 comprising an AlN buffer layer 20T to which a dislocation blocking layer 24 for reducing crystallographic defects is added between the surface protection layer 22 and the smoothing layer 26. In another embodiment a deep UV light-emitting device is provided.

Abstract: To improve light extraction efficiency of a deep ultraviolet light-emitting diode (DUVLED), a typical LED element has a single crystal substrate made of sapphire or AlN, The ultraviolet layer is arranged as a film stack having an n-type conductive layer, a recombination layer, and a p-type conductive layer. A stack of a p-type contact layer and a reflective electrode is disposed on the p-type conductive layer. The ultraviolet emission layer and a p-type contact layer are made of mixed crystal of AlN and GaN. The transmittance for the emission wavelength of the p-type contact layer is increased, and the light extraction efficiency is improved. Also an LED element whose p-type contact layer is configured in a layered structure and whose reflective electrode is patterned is provided. Moreover, an electric appliance having such LED elements is provided.

Abstract: To improve light extraction efficiency of a deep ultraviolet light-emitting diode (DUVLED), a typical LED element has a single crystal substrate made of sapphire or AlN, The ultraviolet layer is arranged as a film stack having an n-type conductive layer, a recombination layer, and a p-type conductive layer. A stack of a p-type contact layer and a reflective electrode is disposed on the p-type conductive layer. The ultraviolet emission layer and a p-type contact layer are made of mixed crystal of AlN and GaN. The transmittance for the emission wavelength of the p-type contact layer is increased, and the light extraction efficiency is improved. Also an LED element whose p-type contact layer is configured in a layered structure and whose reflective electrode is patterned is provided. Moreover, an electric appliance having such LED elements is provided.