III-NITRIDE SEMICONDUCTOR LIGHT EMITTING DEVICE

摘要

A group III nitride semiconductor light emitting device is provided to reduce a growth time and a cost as the growth rate of GaN is faster than the growth rate of AlGaN. A group III nitride semiconductor light emitting device(11) comprises a n-type gallium nitride semiconductor layer, a first p-type AlXGa1- XN(0<=X<1) layer(15), a light-emitting layer, a second p-type AlYGa1- YN(0<=Y<=X<1) layer(17), a third p-type AlZGa1-ZN layer(0<=Z<=Y<=X<1)(21) and a p electrode. The light-emitting layer is installed between the n-type gallium nitride semiconductor layer and the first p-type AlXGa1-XN layer. The light-emitting layer comprises an InGaN layer. The second P-type AlYGa1- YN(0<=Y<=X<1) layer is installed on the first p-type AlXGa1-XN layer. The third P-type AlZGa1-ZN layer(0<=Z<=Y<=X<1) is installed on the second P-type AlYGa1-YN layer. The p electrode is contacted to the third P-type AlZGa1-ZN layer. The p-type dopant concentration of the second P-type AlYGa1-YN layer is greater than the p-type dopant concentration of the first p-type AlXGa1-XN layer and third p-type AlZGa1-ZN layer.