Band offset in AlInGaP based light emitters to improve temperature performance
View Patent ↗Systems and methods for improving the temperature performance of AlInGaP based light emitters. Nitrogen is added to the quantum wells in small quantities. Nitrogen is added in a range of about 0.5 percent to 2 percent. The addition of nitrogen increases the conduction band offset and increases the separation of the indirect conduction band. To keep the emission wavelength in a particular range, the concentration of In in the quantum wells may be decreased or the concentration of Al in the quantum wells may be increased. Because the depth of the quantum wells in the valence band is more than is required although the addition of nitrogen reduces the depth of the quantum wells in the valence band. The net result is an increase in the conduction band offset and an increase in the separation of the indirect conduction band.
1. A semiconductor light emitter comprising:
n-type distributed Bragg reflector (DBR) layers;
p-type DBR layers;
an active region arranged between the n-type DBR layers and the p-type DBR layers, the active region being configured to emit light in the visible spectrum; and
a plurality of quantum wells formed in the active region and separated by barrier layers, wherein each quantum well comprises AlInGaPN, wherein the concentration of nitrogen causes an increased conduction band offset of the active region compared to the active region without the concentration of nitrogen and affects an emission wavelength by changing a bandgap of the light emitter, wherein a concentration of In is reduced or concentration of Al is increased to maintain the emission wavelength in a particular range.
2. A semiconductor light emitter as defined in claim 1 , wherein the concentration of nitrogen is in a range from about 0.2 percent to about 2.5 percent.
3. A semiconductor light emitter as defined in claim 1 , wherein the concentration of nitrogen is in a range of 0.5 percent to 2 percent.
4. A semiconductor light emitter as defined in claim 1 , wherein the concentration of In is reduced to maintain the emission wavelength in a particular range.
5. A semiconductor light emitter as defined in claim 1 , wherein the concentration of Al is increased to maintain the emission wavelength in a particular range.
6. A semiconductor light emitter as defined in claim 1 , wherein the concentration of nitrogen increases the indirect band gap of the active region compared to the indirect bandgap of the active region where the nitrogen is not included.
7. A semiconductor light emitter comprising:
an n-type layer;
a p-type layer;
an active region arranged between the n-type layer and the p-type layer, the active having a plurality of quantum wells and a plurality of quantum well barriers that are configured to emit light in the visible spectrum;
each quantum well including AlInGaPN; and
a concentration of nitrogen included in the active region, wherein the concentration of nitrogen causes an increased conduction band offset of the active region compared to the active region without the concentration of nitrogen and affects an emission wavelength by changing a bandgap of the light emitter, wherein a concentration of In in the quantum wells is reduced or concentration of Al in the quantum wells is increased to maintain the emission wavelength in a particular range.
8. A semiconductor light emitter as defined in claim 7 , wherein the concentration of nitrogen is in a range from about 0.2 percent to about 2.5 percent.
9. A semiconductor light emitter as defined in claim 7 , wherein the concentration of nitrogen is in a range of 0.5 percent to 2 percent.
10. A semiconductor light emitter as defined in claim 7 , wherein the concentration of In is reduced to maintain the emission wavelength in a particular range.
11. A semiconductor light emitter as defined in claim 7 , wherein the concentration of Al is increased to maintain the emission wavelength in a particular range.
12. A semiconductor light emitter as defined in claim 7 , wherein the concentration of nitrogen increases the indirect band gap of the active region compared to the indirect bandgap of the active region where the nitrogen is not included.
13. A semiconductor light emitter as defined in claim 7 , wherein the n-type layer further comprises Distributed Bragg Reflector layers and the p-type layer further comprises Distributed Bragg Reflector layers.
14. A semiconductor light emitter comprising:
an n-type layer;
a p-type layer;
an active region positioned between the n-type layer and the p-type layer, the active region having a plurality of quantum wells and a plurality of quantum well barriers, at least a portion of the active region comprising AlInGaPN wherein the nitrogen concentration is in a range from about 0.2 percent to about 2.5 percent and the active region is configured to emit light in the visible spectrum, wherein the concentration of nitrogen causes an increased conduction band offset of the active region compared to the active region without the concentration of nitrogen and affects an emission wavelength by changing a bandgap of the light emitter, wherein a concentration of In is reduced or concentration of Al is increased to maintain the emission wavelength in a particular range.
15. A semiconductor light emitter as defined in claim 14 , wherein the active concentration of nitrogen is in a range from 0.5 percent to 2.0.
16. A semiconductor light emitter as defined in claim 14 , further comprising a first DBR and a second DBR.