Epitaxial structure of semiconductor light-emitting element, semiconductor light-emitting element, and light-emitting device
An epitaxial structure of a semiconductor light-emitting element includes an n-type layer, a V-pit control layer, a light-emitting layer, and a p-type layer stacked from bottom to top. The light-emitting layer includes a plurality of well layers and a plurality of barrier layers stacked alternately. The V-pit control layer includes a first superlattice layer, and a distance between a bottom surface of the V-pit control layer and a bottom surface of the first superlattice layer is less than or equal to 0.15 μm. The bottom surface of the first superlattice layer and a bottom surface of the light-emitting layer have a distance therebetween ranging from 0.05 μm to 0.3 μm, and each of the first superlattice layer and the light-emitting layer is an Indium (In)-containing layer. A semiconductor light-emitting element and a light-emitting device are also provided.
1 . An epitaxial structure of a semiconductor light-emitting element, comprising an n-type layer, a V-pit control layer, a light-emitting layer and a p-type layer which are stacked sequentially in such order from bottom to top, said light-emitting layer including a plurality of well layers and a plurality of barrier layers stacked alternately, and said well layers having a bandgap energy less than a bandgap energy of said barrier layers;
wherein said V-pit control layer includes a first superlattice layer, a distance between a bottom surface of said V-pit control layer and a bottom surface of said first superlattice layer is less than or equal to 0.15 μm, said bottom surface of said first superlattice layer and a bottom surface of said light-emitting layer have a distance therebetween ranging from 0.05 μm to 0.3 μm, and each of said first superlattice layer and said light-emitting layer is an Indium (In)-containing layer.
2 . The epitaxial structure as claimed in claim 1 , wherein said V-pit control layer has a carbon (C) doping concentration greater than a C doping concentration of said n-type layer, said C doping concentration of said V-pit control layer being greater than or equal to 2×10 16 atoms/cm 3 and less than or equal to 5×10 17 atoms/cm 3 .
3 . The epitaxial structure as claimed in claim 2 , wherein said V-pit control layer has a silicon (Si) doping concentration ranging from 1×10 17 atoms/cm 3 to 1×10 19 atoms/cm 3 .
4 . The epitaxial structure as claimed in claim 3 , wherein said C doping concentration of said V-pit control layer is greater than or equal to 2×10 16 atoms/cm 3 and less than or equal to 8×10 16 atoms/cm 3 .
5 . The epitaxial structure as claimed in claim 3 , wherein said V-pit control layer is multilayered and at least includes a gallium nitride (GaN) layer.
6 . The epitaxial structure as claimed in claim 3 , wherein said V-pit control layer has a thickness less than or equal to 0.4 μm.
7 . The epitaxial structure as claimed in claim 1 , wherein said V-pit control layer further includes a first layer structure disposed below said first superlattice layer, a bottom surface of said first layer structure being said bottom surface of said V-pit control layer, said first layer structure having a Si doping concentration ranging from 2×10 18 atoms/cm 3 to 1×10 19 atoms/cm 3 , said Si doping concentration of said first layer structure being greater than a Si doping concentration of said first superlattice layer and a Si doping concentration of a top surface of said n-type layer.
8 . The epitaxial structure as claimed in claim 7 , wherein said first layer structure has a thickness less than or equal to 0.15 μm and greater than or equal to 0.02 μm.
9 . The epitaxial structure as claimed in claim 1 , wherein said V-pit control layer further includes a third layer structure disposed above said first superlattice layer, said third layer structure having a Si doping concentration greater than said Si doping concentration of said first superlattice layer, said Si doping concentration of said third layer structure ranging from 1×10 18 atoms/cm 3 to 1×10 19 atoms/cm 3 .
10 . The epitaxial structure as claimed in claim 9 , wherein said third layer structure has a thickness less than or equal to 0.1 μm and greater than or equal to 0.01 μm.
11 . The epitaxial structure as claimed in claim 9 , wherein said third layer structure has a C doping concentration less than or equal to a C doping concentration of said first superlattice layer.
12 . The epitaxial structure as claimed in claim 9 , wherein each period of said first superlattice layer of said V-pit control layer has stacked layers of In x Ga 1-x N/In y Ga 1-y N, an initial layer of said first superlattice layer being an In y Ga 1-y N layer, and a terminal layer of said first superlattice layer being an In x Ga 1-x N layer, where x>y, 0<x<1, and 0≤y<1.
13 . The epitaxial structure as claimed in claim 9 , wherein each period of said first superlattice layer of said V-pit control layer has stacked layers of In x Ga 1-x N/In y Ga 1-y N, an initial layer of said first superlattice layer being an In x Ga 1-x N layer, and a terminal layer of said first superlattice layer being an In y Ga 1-y N layer, where x>y, 0<x<1, and 0≤y<1.
14 . The epitaxial structure as claimed in claim 9 , wherein said third layer structure is an InGaN layer or a GaN layer, said InGaN layer having an In content less than an In content of each of In-containing sublayers of said first superlattice layer.
15 . The epitaxial structure as claimed in claim 14 , wherein each period of said first superlattice layer of said V-pit control layer has stacked layers of In x Ga 1-x N/In y Ga 1-y N, where x>y, 0<x<1, and 0≤y<1, said third layer structure having a thickness greater than a thickness of an In y Ga 1-y N layer of each period of said stacked layers of In x Ga 1-x N/In y Ga 1-y N.
16 . The epitaxial structure as claimed in claim 9 , wherein a top surface of said third layer structure is in contact with a bottom surface of a first sublayer of said light-emitting layer containing indium.
17 . The epitaxial structure as claimed in claim 1 , wherein the number of periods of said first superlattice layer is 3 to 7.
18 . The epitaxial structure as claimed in claim 1 , which further includes a second superlattice layer disposed between said V-pit control layer and said light-emitting layer, said second superlattice layer having a thickness less than or equal to 0.1 μm and greater than or equal to 0.02 μm.
19 . The epitaxial structure as claimed in claim 18 , wherein said second superlattice layer has a C doping concentration less than or equal to a C doping concentration of said V-pit control layer.
20 . The epitaxial structure as claimed in claim 1 , wherein said n-type layer includes an electron injection layer and a current spreading layer disposed on said electron injection layer, said current spreading layer being disposed between said V-pit control layer and said electron injection layer, said electron injection layer having a Si doping concentration greater than a Si doping concentration of said current spreading layer, said Si doping concentration of said current spreading layer being less than a Si doping concentration of said V-pit control layer.
21 . A semiconductor light-emitting element, comprising an epitaxial structure as claimed in claim 1 .
22 . A light-emitting device, comprising a semiconductor light-emitting element as claimed in claim 21 .