Monolithic, segmented light emitting diode array
A light-emitting device is disclosed which includes a segmented active layer disposed between a segmented conductivity layer and a continuous conductivity layer, the active layer, the segmented conductivity layer, and the continuous conductivity layer being arranged to define a plurality of pixels, each pixel including a different segment of the segmented conductivity layer and the segmented active layer. A continuous wavelength converting layer disposed on the continuous conductivity layer is provided. A plurality of first contacts, each first contact being electrically connected to a different segment of the segmented conductivity layer is provided. One or more second contacts that are electrically connected to the continuous conductivity layer are also provided, the number of second contacts being less than the number of first contacts.
1. A device comprising:
a segmented first conductivity layer, a segmented active layer, and a second conductivity layer, arranged in a cascading arrangement with each segment of the active layer between the second conductivity layer and a corresponding segment of the first conductivity layer so as to form a corresponding pixel of a plurality of pixels, each segment of the first conductivity layer leaving exposed a peripheral portion of a surface of the corresponding segment of the active layer;
a wavelength converting layer disposed on a corresponding portion of a surface of the second conductivity layer opposite a surface thereof that faces the segments of the active layer;
a plurality of first contacts, each first contact being electrically connected to a corresponding segment of the first conductivity layer different from other segments connected to other first contacts of the plurality; and
one or more second contacts that are electrically connected to the second conductivity layer.
2. The device of claim 1 , wherein each of the pixels has a width between 100 and 500 microns.
3. The device of claim 1 , further comprising an optically isolating material formed in one or more of a plurality of trenches separating adjacent segments of the active layer from one another.
4. The device of claim 3 , wherein the optically isolating material includes one or more of a reflective material, a distributed Bragg reflector (DBR), an absorptive material, or a scattering material.
5. The device of claim 1 , wherein the wavelength converting layer includes phosphor particles.
6. The device of claim 1 , further comprising a passivation layer between the wavelength converting layer and the second conductivity layer.
7. The device of claim 3 , wherein the optically isolating material separates adjacent segments of the first conductivity layer from one other.
8. The device of claim 1 , wherein each one of the pixels is arranged so as to emit light in response to current flowing through the corresponding first contact.
9. The device of claim 1 , wherein the second conductivity layer is a continuous conductivity layer.
10. The device of claim 9 , wherein the second contacts are fewer in number than the first contacts.
11. The device of claim 1 , wherein:
the second conductivity layer is a segmented layer, each pixel including a corresponding segment of the second conductivity layer in the cascading arrangement, each segment of the active layer leaving exposed a peripheral portion of a surface of the corresponding segment of the second conductivity layer; and
each one of a plurality of the second contacts is electrically connected to a corresponding segment of the second conductivity layer different from other second contacts of the plurality.
12. The device of claim 11 , further comprising an optically isolating material formed in one or more of a plurality of trenches separating adjacent segments of the second conductivity layer from one another.
13. The device of claim 12 , wherein the optically isolating material includes one or more of a reflective material, a distributed Bragg reflector (DBR), an absorptive material, or a scattering material.
14. The device of claim 12 , wherein the optically isolating material separates adjacent segments of the active layer from one other.
15. The device of claim 14 , wherein the optically isolating material separates adjacent segments of the first conductivity layer from one other.
16. The device of claim 1 , wherein the wavelength converting layer is a continuous layer.
17. The device of claim 1 , wherein the wavelength converting layer is segmented, each segment of the wavelength converting layer being disposed on a corresponding portion of a surface of the second conductivity layer opposite a surface thereof that faces a corresponding one of the segments of the active layer.
18. The device of claim 17 , further comprising an optically isolating material formed in one or more of a plurality of trenches at least partly separating adjacent segments of the wavelength converting layer from one another.
19. The device of claim 17 , wherein the optically isolating material includes one or more of a reflective material, a distributed Bragg reflector (DBR), an absorptive material, or a scattering material.
20. The device of claim 1 , further comprising a light-extraction pattern formed between the second conductivity layer and the wavelength converting layer.