NANO STRUCTURED LEDS

• US 20110079796A1
• Filed: 10/05/2009
• Published: 04/07/2011
• Est. Priority Date: 10/05/2009
• Status: Active Grant

• Current Assignee: Zena Technologies, Inc.
• Original Assignee: Zena Technologies, Inc.
• Inventors: WOBER, Munib
• Granted Patent: US 8,791,470 B2
• Time in Patent Office: Days
• US Class Current: 257/82
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 27/14 including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation radiation-sensitive components structurally associated with one or more electric light sources only H01L31/14; couplings of light guides with optoelectronic elements G02B6/42
• CPC Class Codes: H01L 27/1446 in a repetitive configuration
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 31/153 formed in, or on, a common substrate
• CPC Class Codes: H01L 33/0012 p-i-n devices
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: Y10S 977/762 Nanowire or quantum wire, i.e. axially elongated structure having two dimensions of 100 nm or less
• CPC Class Codes: Y10S 977/95 Electromagnetic energy

Abstract

An embodiment relates to a nanowire-containing LED device with optical feedback comprising a substrate, a nanowire protruding from a first side the substrate, an active region to produce light, a optical sensor and a electronic circuit, wherein the optical sensor is configured to detect at least a first portion of the light produced in the active region, and the electronic circuit is configured to control an electrical parameter that controls a light output of the active region. Yet, another embodiment relates to an image display having the nanowire-containing LED device with optical feedback.

Claims

1. A device comprising a substrate, a nanowire protruding from a first side of the substrate, an active region to produce light, a optical sensor and a electronic circuit, wherein the optical sensor is configured to detect at least a first portion of the light produced in the active region, and the electronic circuit is configured to control an electrical parameter that controls a light output of the active region.

2. The device of claim 1, wherein the active region comprises a PN junction or a PIN-junction.

3. The device of claim 1, wherein an output of the optical sensor is an input to the control electronic circuit.

4. The device of claim 1, wherein the electrical parameter comprises voltage or current.

5. The device of claim 1, wherein the electronic circuit is configured to control voltage or current such that the light output is maintained substantially constant irrespective of a temperature of the active region within an operating temperature range of the active region.

6. The device of claim 1, wherein the optical sensor comprises a PN or PIN photodiode having a performance characteristic that is substantially insensitive to a temperature in an operating temperature range of the active region.

7. The device of claim 1, wherein the electronic circuit is configured to control voltage or current such that the light output is maintained substantially constant irrespective of composition variations of the active region within and among the different active elements.

8. The device of claim 1, wherein at least a portion of the light produced in the active region is directed in a direction given by the nanowire.

9. The device of claim 1, wherein the nanowire is configured to both produce light and form a waveguide.

10. The device of claim 1, further comprising a volume element, wherein a portion of the nanowire and a portion of the volume element are configured to form the active region.

11. The device of claim 10, wherein the volume element comprises a doping layer configured to provide a p or n region and a well layer.

12. The device of claim 1, wherein the optical sensor comprises a pinned photodiode in the substrate.

13. The device of claim 1, further comprising a partially reflective layer on the substrate surrounding and/or within the nanowire, wherein the partially reflective layer is configured to allow the first portion of the light to transmit through the partially reflective layer to the optical sensor and to allow at least a second portion of the light to reflect from a surface of the partially reflective layer.

14. The device of claim 1, further comprises one or more cladding layers surrounding the nanowire, wherein the one or more cladding layers are configured such that the nanowire is configured to form a waveguide.

15. The device of claim 13, wherein the one or more cladding layers are configured to provide a graded refractive index such that a refractive index of the nanowire is higher than that of the one or more cladding layer.

16. The device of claim 1, wherein the device comprises a plurality of the nanowires comprising different materials emit different ranges of wavelengths of light.

17. The device of claim 1, wherein the device comprises a plurality of the nanowires comprising different diameters that form waveguides for different ranges of wavelengths of light.

18. The device of claim 1, wherein the device comprises a plurality of the nanowires comprising different materials emit different ranges of wavelengths of light and the device comprises a plurality of the nanowires comprising different diameters that form waveguides for different ranges of wavelengths of light.

19. The device of claim 1, wherein the nanowire and the volume element are arranged to direct the light through the nanowire and the substrate such that the light is emitted from a second side of the substrate opposite the first side.

20. The device of claim 1, wherein the substrate comprises a light emitting diode (LED) that is optically coupled to the nanowire.

21. The device of claim 10, wherein the volume element is configured to spread the light by dispersion at a junction between the nanowire and the volume element.

22. The device of claim 1, wherein the electronic circuit comprises a controller configured to calibrate the electrical parameter.

23. The device of claim 22, wherein the controller comprises memory, the memory comprising values for controlling the electrical parameter so that the light output is set by the values stored in the memory.

24. The device of claim 22, wherein the controller comprises memory, wherein the controller is configured to calibrate the electrical parameter to cause the light output to more closely match a target output based on target values of the light output stored in the memory.

25. The device of claim 24, wherein the target values represent current values for different colors of the light.

26. The device of claim 24, wherein the target values represent target brightness levels.

27. The device of claim 1, further comprising a low-index material having a lower refractive index surrounding the nanowire and a metal layer surrounding the low-index material.

28. The device of claim 1, wherein the device is an electronic chip.

29. The device of claim 28, wherein the active region produces only a single color light.

30. The device of claim 24, wherein the electronic chip comprises at least a first active region for emitting a first color, a second active region for emitting a second color, and a third active region for emitting a third color.

31. The device of claim 28, wherein the chip does not include a color filter.

32. An image display comprising a device of claim 1.

33. The image display of claim 32, wherein the device comprises at least a first active region for emitting a first color, a second active region for emitting a second color, and a third active region for emitting a third color.

34. The image display of claim 32, wherein the image display does not include a color filter.

35. The image display of claim 32, wherein the device comprises at least a first electrical parameter to control emission of the first color, a second electrical parameter to control emission of the second color, and a third electrical parameter to control emission of the third color.

36. The image display of claim 32, wherein the optical sensor comprises a PN or PIN photodiode having a performance characteristic that is substantially insensitive to a temperature in an operating temperature range of the active region.

37. The image display of claim 32, wherein the optical sensor comprises a PN or PIN photodiode having a performance characteristic that is substantially insensitive to composition variations of the active region.

38. The image display of claim 32, wherein the image display comprises a television system on a chip.

39. The image display of claim 32, wherein the image display comprises a micro-display.

40. The image display of claim 32, further comprising a lens configured to project the light on a screen.

41. The image display of claim 32, wherein the substrate comprises silicon.

42. The image display of claim 41, wherein the nanowire comprises materials that emits red, green or blue light.

43. The device of claim 30, wherein the first, second and third colors are red, green and blue, respectively.