Semiconductor light-emitting device and manufacturing method thereof

The invention discloses a semiconductor light-emitting device and a manufacturing method thereof. The semiconductor light-emitting device comprises a substrate, a crystallizing layer formed on the substrate, a gallium nitride buffering layer, an N-type gallium nitride layer, a transition layer, a multi-quantum-well layer and a P-type gallium nitride layer and further comprises a low-temperature gallium nitride layer and a stress release layer, wherein the low-temperature gallium nitride layer is formed on the N-type gallium nitride layer, a plurality of concave pits are formed in the low-temperature gallium nitride layer, the thickness of the stress release layer is smaller than 100 nm, the stress release layer is composed of 1-K layers of Inx(k)Ga1- x(K)N which are sequentially formed on the low-temperature gallium nitride layer, the thickness d of the kth layer of Inx(k)Ga1- x(K)N is smaller than the thickness d of the (k-1)th layer of Inx(k-1)Ga1- x(K-1)N, x(k) is larger than x(k-1), k is equal to 1,...,K, and K is smaller than or equal to 5; the concave pits are covered with the P-type gallium nitride layer. The number of the InGaN layers in the stress release layer and the overall thickness are adjusted according to In components of quantum wells so that the In components of the InGaN layers can be gradually increased from the bottom layer to the surface, the thickness is gradually reduced, and the purpose of gradually releasing stress is achieved.