P-contact layer for a III-P semiconductor light emitting device
View Patent ↗A device includes a semiconductor structure with at least one III-P light emitting layer disposed between an n-type region and a p-type region. The semiconductor structure further includes a GaAs x P 1-x p-contact layer, wherein x<0.45. A first metal contact is in direct contact with the GaAs x P 1-x p-contact layer. A second metal contact is electrically connected to the n-type region. The first and second metal contacts are formed on a same side of the semiconductor structure.
1. A device comprising:
a semiconductor structure comprising:
at least one III-P light emitting layer disposed between an n-type region and a p-type region;
a GaAs x P 1-x p-contact layer, wherein x<0.45;
a first metal contact in direct contact with the GaAs x P 1-x p-contact layer comprising:
a mirror; and
a plurality of ohmic contact regions disposed between the mirror and the GaAs x P 1-x p-contact layer; and
a second metal contact electrically connected to the n-type region;
wherein the first and second metal contacts are formed on opposite sides of the semiconductor structure.
2. The device of claim 1 wherein the GaAs x P 1-x p-contact layer has a graded composition x.
3. The device of claim 1 wherein the GaAs x P 1-x p-contact layer has a composition graded from x=0 to x <0.45.
4. The device of claim 1 wherein the mirror comprises silver, Al, or Au, dielectric layers (SiO 2 or Si 1-x N x ), and the plurality of ohmic contact regions comprise one of AuZn, Al, indium tin oxide (ITO).
5. The device of claim 1 wherein the GaAs x P 1-x p-contact layer has a constant composition x.
6. The device of claim 5 wherein 0.2<x<0.4.
7. A device comprising:
a semiconductor structure comprising:
at least one III-P light emitting layer disposed between an n-type region and a p-type region;
a GaAs x P 1-x p-contact layer, wherein x<0.45;
a first metal contact in direct contact with the GaAs x P 1-x p-contact layer;
a second metal contact electrically connected to the n-type region;
a cladding layer in direct contact to the III-P light emitting layer; and
a region with a graded composition disposed between the cladding layer and the GaAs x P 1-x p-contact layer;
wherein the first and second metal contacts are formed on opposite sides of the semiconductor structure.
8. The device of claim of claim 7 wherein:
the cladding layer comprises Al 0.5 In 0.5 P; and
the region with graded composition is graded from Al 0.52 In 0.48 P to (Al 0.3 Ga 0.7 ) 0.52 In 0.48 P.
9. The device of claim 7 wherein the GaAs x P 1-x p-contact layer has a graded composition x.
10. The device of claim 7 wherein the GaAs x P 1-x p-contact layer has a composition graded from x=0 to x<0.45.
11. The device of claim 7 wherein the GaAs x P 1-x p-contact layer has a constant composition x.
12. The device of claim 11 wherein 0.2<x<0.4.