Patent ID: 8704208

Claim:
A semiconductor light emitting device, comprising: a first conductive semiconductor layer; an active layer disposed under the first conductive semiconductor layer; a second conductive semiconductor layer disposed between the first conductive semiconductor layer and the active layer; a third conductive semiconductor layer under the active layer; a fourth conductive semiconductor layer disposed under the third conductive semiconductor layer; a first electrode layer disposed on at least one of the first conductive semiconductor layer and the second conductive semiconductor layer; and a second electrode layer disposed under the fourth conductive semiconductor layer, wherein the first and the second conductive semiconductor layers include an n-type dopant and are formed of an AlGaN-based semiconductor, wherein the third and fourth conductive semiconductor layers include a p-type dopant and are formed of an AlGaN-based semiconductor, wherein the third conductive semiconductor layer is disposed between the active layer and the fourth conductive semiconductor layer, wherein the active layer includes a plurality of quantum barrier layers and a plurality of quantum well layers having a material different from the quantum barrier layers, wherein the plurality of quantum well layers include an InGaN semiconductor layer, wherein the plurality of quantum barrier layers include an AlGaN-based semiconductor layer, wherein at least two of the plurality barrier layers have a thickness of about 50 Å to about 300 Å, respectively, wherein a cycle of the quantum barrier layer and the quantum well layer includes a cycle of 2 to 10, and wherein the second conductive semiconductor layer has the thickness thinner than a thickness of the third conductive semiconductor layer.