Group III nitride based LED structures including multiple quantum wells with barrier-well unit interface layers
View Patent ↗Group III nitride based light emitting diode (LED) structures include multiple quantum wells with barrier-well units that include III nitride interface layers. Each interface layer may have a thickness of no greater than about 30% of an adjacent well layers, and a comparatively low concentration of indium or aluminum. One or more interface layers may be present in a barrier-well unit. Multiple barrier-well units having different properties may be provided in a single active region.
1. A light emitting diode comprising:
an active region comprising a plurality of sequentially arranged barrier-well units;
wherein each barrier-well unit comprises an Al a In b Ga 1-a-b N barrier layer and an In c Ga 1-c N well layer; and
wherein at least one barrier-well unit, but fewer than all barrier-well units, of the plurality of sequentially arranged barrier-well units, additionally comprises an Al y In z Ga 1-y-z N interface layer (wherein y>0 and wherein y≥z).
2. The light emitting diode of claim 1 , comprising at least one of the following features (i) to (vi):
(i) c>0.10 and c>2·b;
(ii) 0≤a≤0.50 and 0≤b≤0.10;
(iii) y≤0.10;
(iv) y≥4·z;
(v) z=0; or
(vi) y≤0.05 and 0≤z≤0.01.
3. The light emitting diode of claim 1 , wherein in the at least one barrier-well unit, the Al y In z Ga 1-y-z N interface layer is in contact with the In c Ga 1-c N well layer and is in contact with a barrier layer of an adjacent barrier-well unit of the plurality of sequentially arranged barrier-well units.
4. The light emitting diode of claim 1 , comprising at least one of the following features (i) or (ii):
(i) the Al y In z Ga 1-y-z N interface layer comprises a thickness of no greater than about 30% of the In c Ga 1-c N well layer;
(ii) the Al y In z Ga 1-y-z N interface layer comprises a thickness of no greater than 10 Å.
5. The light emitting diode of claim 4 , wherein the Al y In z Ga 1-y-z N interface layer comprises a thickness of no greater than 4 Å.
6. The light emitting diode of claim 1 , wherein at least one barrier-well unit of the plurality of sequentially arranged barrier-well units comprises an Al w In x Ga 1-w-z N interface layer.
7. The light emitting diode of claim 6 , wherein for the at least one barrier-well unit that comprises an Al w In x Ga 1-w-x N interface layer, the Al w In x Ga 1-w-x N interface layer is provided between and in contact with the Al a In b Ga 1-a-b N barrier layer and the In c Ga 1-c N well layer.
8. The light emitting diode of claim 1 , comprising at least two of the following features (i) to (vi):
(i) c>0.10 and c>2·b;
(ii) 0≤a≤0.50 and 0≤b≤0.10;
(iii) y≤0.10;
(iv) y≥4·z;
(v) z=0; or
(vi) y≤0.05 and 0≤z≤0.01.
9. The light emitting diode of claim 1 , wherein c>0.10 and c>2·b.
10. The light emitting diode of claim 1 , wherein 0≤a≤0.50 and 0≤b≤0.10.
11. The light emitting diode of claim 1 , wherein y≤0.10.
12. The light emitting diode of claim 1 , wherein y≥4·z.
13. The light emitting diode of claim 1 , wherein z=0.
14. The light emitting diode of claim 1 , wherein y≤0.05 and 0≤z≤0.01.