Optical tuning of light emitting semiconductor junctions
Light emitting semiconductor junctions are disclosed. An exemplary light emitting junction has a first electrical contact coupled to a first side of the junction. The exemplary junction also has a second electrical contact coupled to a second side of the junction. The exemplary junction also has a region of set straining material that exerts a strain on the junction and alters both: (i) an optical polarization, and (ii) an emission wavelength of the junction. The region of set straining material is not on a current path between said first electrical contact and said second electrical contact. The region of set straining material covers a third side and a fourth side of the light emitting junction along a cross section of the light emitting junction. The light emitting semiconductor junction device comprises a three-five alloy.
1. An ultraviolet light emitting diode, comprising:
an ultraviolet light emitting junction;
a first electrical contact coupled to a first side of the junction;
a second electrical contact coupled to a second side of the junction; and
a region of set straining material that exerts a strain on the junction and alters both:
(i) an optical polarization, and (ii) an emission wavelength of the junction;
wherein the region of set straining material lies outside a current path that includes the first electrical contact and the second electrical contact; and
the light emitting semiconductor junction device comprises a three-five alloy.
2. The ultraviolet light emitting diode of claim 1 , wherein:
the junction comprises an epitaxy material;
the region of set straining material comprises a non-epitaxy material; and
the optical polarization of the junction, as altered by the strain on the junction, is linear.
3. The ultraviolet light emitting diode of claim 1 , wherein:
the three-five alloy comprises a ternary group-three nitride alloy; and
said ternary group-three nitride alloy comprises gallium.
4. The ultraviolet light emitting diode of claim 1 , wherein:
a structure of the junction is selected from a group consisting of: a lateral p-i-n structure; a superlattice structure; and a multiple quantum well structure.
5. The ultraviolet light emitting diode of claim 1 , wherein:
the region of set straining material comprises a plurality of external stressors.
6. The ultraviolet light emitting diode of claim 5 , wherein:
the plurality of external stressors all contribute a uniaxial component to the strain on the junction.
7. The ultraviolet light emitting diode of claim 5 , wherein:
at least one of the plurality of external stressors contributes a biaxial component to the strain on the junction.
8. The ultraviolet light emitting diode of claim 5 , wherein:
at least one of the plurality of external stressors contributes a triaxial component to the strain on the junction.
9. The ultraviolet light emitting diode of claim 1 , further comprising:
a trench that penetrates a layer of material used to form the junction;
wherein the region of set straining material includes a bottom portion of the trench.
10. The ultraviolet light emitting diode of claim 9 , wherein:
the region of set straining material comprises an oxidized semiconductor material.
11. The ultraviolet light emitting diode of claim 1 , wherein said region of set straining material:
fully encompasses the junction in two directions along a cross section of the junction; and
is in direct contact with an active layer of the junction.
12. The ultraviolet light emitting diode of claim 11 , further comprising:
an n-type layer of the junction, a p-type layer of the junction, and an i-type layer of the junction;
wherein the n-type layer, the p-type layer, and the region of set straining material fully encompass the i-type layer; and
wherein the region of set straining material forms an annular cylinder.
13. The ultraviolet light emitting diode of claim 12 , wherein:
the region of set straining material surrounds a mesa;
the mesa comprises the junction; and
the region of set straining material leaves a top side of the mesa partially exposed to provide the first electrical contact for the junction.
14. The ultraviolet light emitting diode of claim 1 , further comprising:
a substrate layer supporting the junction; and
a buffer layer having a first surface in contact with a top side of the substrate;
wherein the region of set straining material is also in contact with the first surface of the buffer layer.
15. The ultraviolet light emitting diode of claim 14 , wherein:
the region of set straining material is in an excavated portion of the substrate.
16. A light emitting semiconductor junction device, comprising:
a light emitting junction;
a first electrical contact coupled to a first side of the junction;
a second electrical contact coupled to a second side of the junction; and
a region of set straining material that exerts a strain on the junction and alters both:
(i) an optical polarization, and (ii) emission wavelength of the junction;
wherein: the first electrical contact and the second electrical contact provide a current path to the light emitting junction independent of the region of set straining material;
the region of set straining material covers a third side and a fourth side of the light emitting junction along a cross section of the light emitting junction; and
the light emitting semiconductor junction device comprises a three-five alloy.
17. The light emitting semiconductor junction device of claim 16 , wherein:
the light emitting semiconductor junction device is a deep ultraviolet diode;
the light emitting junction comprises a ternary group-three nitride alloy; and
the ternary group-three nitride alloy comprises gallium.
18. The light emitting semiconductor junction device of claim 17 , wherein:
the light emitting junction comprises aluminum.
19. The light emitting semiconductor junction device of claim 16 , wherein:
the light emitting semiconductor junction device is a vertical p-i-n deep ultraviolet diode; and
the region of set straining material forms an annular cylinder.
20. The light emitting semiconductor junction device of claim 16 , wherein:
said light emitting semiconductor junction device is a lateral p-i-n ultraviolet diode; and
the region of set straining material covers a fifth side of the light emitting junction along the cross section.
21. A light emitting semiconductor junction device, comprising:
a light emitting junction;
a first electrical contact coupled to a first side of the junction;
a second electrical contact coupled to a second side of the junction; and
a region of set straining material that exerts a strain on the junction and alters both: (i) an optical polarization, and (ii) emission wavelength of the junction;
wherein: the region of set straining material is not on a current path between said first electrical contact and said second electrical contact;
said region of set straining material covers a third side and a fourth side of the light emitting junction along a cross section of the light emitting junction;
the light emitting semiconductor junction device comprises a three-five alloy.
22. The light emitting semiconductor junction device of claim 21 , further comprising:
a trench that penetrates a layer of material used to form the junction; and
an oxidized polysilicon material formed in the trench;
wherein the region of set straining material comprises the oxidized polysilicon material.
23. The light emitting semiconductor junction device of claim 21 , further comprising:
a trench that penetrates a layer of material used to form the junction;
wherein the region of set straining material comprises a metal-oxide of the layer of material.
24. The light emitting semiconductor junction device of claim 21 , wherein:
the light emitting semiconductor junction device is an ultraviolet diode;
the light emitting semiconductor junction device comprises a ternary group-three nitride alloy; and
the ternary group-three nitride alloy comprises gallium and aluminum.
25. The light emitting semiconductor junction device of claim 24 , further comprising:
a trench that penetrates a layer of the ternary group-three nitride alloy;
wherein the region of set straining material comprises a metal-oxide of the ternary group-three nitride alloy.