There is presented a light emitting device, having plural light emitting elements disposed on a substrate, in which a protection element, such as a zener diode, can be disposed at an appropriate position. The light emitting device includes: a substrate; a light emitting section having plural light emitting elements disposed in a mounting area on the substrate; a positive electrode and negative electrode each having a pad section and wiring section to apply voltage to the light emitting section through the wiring sections; a protection element disposed at one of the positive electrode and negative electrode and electrically connected with the other one electrode; and a light reflecting resin formed on the substrate such as to cover at least the wiring sections and the protection element, wherein the wiring sections are formed along the periphery of the mounting area such that one end portions thereof are adjacent to each other.

There is presented a light emitting device, having plural light emitting elements disposed on a substrate, in which a protection element, such as a zener diode, can be disposed at an appropriate position. The light emitting device includes: a substrate; a light emitting section having plural light emitting elements disposed in a mounting area on the substrate; a positive electrode and negative electrode each having a pad section and wiring section to apply voltage to the light emitting section through the wiring sections; a protection element disposed at one of the positive electrode and negative electrode and electrically connected with the other one electrode; and a light reflecting resin formed on the substrate such as to cover at least the wiring sections and the protection element, wherein the wiring sections are formed along the periphery of the mounting area such that one end portions thereof are adjacent to each other.

A light emitting diode device has a bulk gallium and nitrogen containing substrate with an active region. The device has a lateral dimension and a thick vertical dimension such that the geometric aspect ratio forms a volumetric diode that delivers a nearly uniform current density across the range of the lateral dimension.

A light emitting diode device has a bulk gallium and nitrogen containing substrate with an active region. The device has a lateral dimension and a thick vertical dimension such that the geometric aspect ratio forms a volumetric diode that delivers a nearly uniform current density across the range of the lateral dimension.

A semiconductor structure (100) comprising: a substrate (102), a first layer (106) of Al.sub.XGa.sub.YIn.sub.(1−X−Y)N disposed on the substrate, stacks (107, 109) of several second and third layers (108, 110) alternating against each other, between the substrate and the first layer, a fourth layer (112) of Al.sub.XGa.sub.YIn.sub.(1−X−Y)N, between the stacks, a relaxation layer of AlN disposed between the fourth layer and one of the stacks, and, in each of the stacks: the level of Ga of the second layers increases from one layer to the next in a direction from the substrate to the first layer, the level of Ga of the third layers is constant or decreasing from one layer to the next in said direction, the average mesh parameter of each group of adjacent second and third layers increasing from one group to the next in said direction, the thickness of the second and third layers is less than 5 nm.

A semiconductor structure (100) comprising: a substrate (102), a first layer (106) of Al.sub.XGa.sub.YIn.sub.(1−X−Y)N disposed on the substrate, stacks (107, 109) of several second and third layers (108, 110) alternating against each other, between the substrate and the first layer, a fourth layer (112) of Al.sub.XGa.sub.YIn.sub.(1−X−Y)N, between the stacks, a relaxation layer of AlN disposed between the fourth layer and one of the stacks, and, in each of the stacks: the level of Ga of the second layers increases from one layer to the next in a direction from the substrate to the first layer, the level of Ga of the third layers is constant or decreasing from one layer to the next in said direction, the average mesh parameter of each group of adjacent second and third layers increasing from one group to the next in said direction, the thickness of the second and third layers is less than 5 nm.

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 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.

Embodiments relate to a light emitting device, a light emitting device package, and a lighting system comprising the same. The light emitting device according to embodiments may comprise: a first conductivity-type semiconductor layer; an active layer on the first conductivity-type semiconductor layer; an electron blocking layer on the active layer; and a second conductivity-type semiconductor layer on the electron blocking layer. The electron blocking layer may comprise an In.sub.xAl.sub.yGa.sub.1-x-yN based superlattice layer (wherein 0≦x≦1, 0≦y≦1).

Embodiments relate to a light emitting device, a light emitting device package, and a lighting system comprising the same. The light emitting device according to embodiments may comprise: a first conductivity-type semiconductor layer; an active layer on the first conductivity-type semiconductor layer; an electron blocking layer on the active layer; and a second conductivity-type semiconductor layer on the electron blocking layer. The electron blocking layer may comprise an In.sub.xAl.sub.yGa.sub.1-x-yN based superlattice layer (wherein 0≦x≦1, 0≦y≦1).