Gallium nitride-based semiconductor light-emitting device
View Patent ↗A gallium nitride-based semiconductor light-emitting device includes a sapphire substrate having a nitridated upper surface; a polarity conversion layer formed on the sapphire substrate and made of MgN-based single ciystals; a first conductive gallium nitride-based semiconductor layer formed on the polarity conversion layer; an active layer formed on the first conductive gallium nitride-based semiconductor layer; and a second conductive gallium nitride-based semiconductor layer formed on the active layer.
1. A gallium nitride-based semiconductor light-emitting device compnsing:
a sapphire substrate having a nitridated upper surface;
a polarity conversion layer formed on the sapphire substrate and made of MgN-based single crystals;
a first conductive gallium nitride-based semiconductor layer formed on the polarity conversion layer;
an active layer formed on the first conductive gallium nitride-based semiconductor layer; and
a second conductive gallium nitride-based semiconductor layer formed on the active layer;
wherein the polarity conversion layer is made of material satisfying a composition formula of (Al x Ga y In z )Mg 3−(x+y+z) N 2 wherein 0≦x,y,z≦1, and 0<x+y+z<3.
2. The device as set forth in claim 1 , wherein the polarity conversion layer is formed by an MBE or MOCVD method.
3. The device as set forth in claim 1 , further comprising:
a buffer layer formed between the sapphire substrate and the polarity conversion layer.
4. The device as set forth in claim 1 , wherein the polarity conversion layer has a thickness of 0.001 to 0.5 μm.
5. The device as set forth in claim 1 , wherein the nitridated upper surface of the a sapphire substrate comprises nitrogen dangling bonds which are bonded to Mg of said MgN-based single crystals of said polarity conversion layer.
6. A gallium nitride-based semiconductor light-emitting device compnsmg:
a sapphire substrate having a nitridated upper surface;
a polarity conversion layer formed on the sapphire substrate and made of MgN-based single crystals;
a first conductive gallium nitride-based semiconductor layer formed on the polarity conversion layer;
an active layer formed on the first conductive gallium nitride-based semiconductor layer; and
a second conductive gallium nitride-based semiconductor layer formed on the active layer;
wherein the polarity conversion layer is made of material satisfying a composition formula of Si a Mg 3-a N 2 wherein 0<a<1.
7. The device as set forth in claim 6 , wherein the polarity conversion layer is formed by an MBE or MOCVD method.
8. The device as set forth in claim 6 , further comprising:
a buffer layer formed between the sapphire substrate and the polarity conversion layer.
9. The device as set forth in claim 6 , wherein the poiarity conversion layer has a thickness of 0.001 to 0.5 μm.
10. The device as set forth in claim 6 , wherein the nitridated upper surface of the a sapphire substrate comprises nitrogen dangling bonds which are bonded to Mg of said MgN-based single crystals of said polarity conversion layer.