Publication NumberUS 20120132278
Assignees
  • The Regents of the University of California
Filing StatusPatent Application
US PAIR StatusAbandoned -- Failure to Respond to an Office Action
US PAIR Status Date2015-06-30
Application Number13/193010
AvailabilityUnknown
Filing Date2011-07-28
Publication Date2012-05-31

Abstract

An apparatus is disclosed including a wave-guide containing a luminescent material which responds to incident light by emitting frequency-shifted light. A first portion of the frequency-shifted light is internally reflected within the wave-guide to a wave-guide output, and a second portion of the frequency-shifted light is transmitted out of the wave-guide. The apparatus further includes a diffuse reflector positioned proximal to the waveguide to reflect at least some of the second portion of the frequency-shifted light hack in to the waveguide to be internally reflected within the wave-guide to a wave-guide output.

Claims

  • 1. An apparatus comprising; a wave-guide containing a luminescent material which responds to incident light by emitting frequency-shifted light, wherein a first portion of the frequency-shifted light is internally reflected within the wave-guide to a wave-guide output, and a second portion of the frequency-shifted light is transmitted out of the wave-guide; and a diffuse reflector positioned proximal to the waveguide to reflect at least some of the second portion of the frequency-shifted light back in to the waveguide to be internally reflected within the wave-guide to a wave-guide output.
  • 2. The apparatus of claim 1, further comprising an absorber positioned proximal to the wave-guide to produce energy in response to the frequency-shifted light.
  • 3. The apparatus of claim 2, wherein the absorber comprises a photovoltaic device.
  • 4. The apparatus of claim 1, wherein the diffuse reflector reflects greater than about 90% of the frequency shifted light incident upon it.
  • 5. The apparatus of claim 1, wherein the luminescent material comprises quantum dots or an organic dye.
  • 6. The apparatus of claim 5, wherein the quantum dots comprise particles ranging between about 1 to 10 nanometers in size.
  • 7. The apparatus of claim 5, wherein the quantum dots comprise material selected from the group consisting of lead sulfide (PbS), cadmium selenide (CdSe), cadmium sulfide (CdS), indium arsenide (InAs), and indium phosphide (InP).
  • 8. The apparatus of claim 5, wherein the quantum dots comprise material selected from the group consisting of zinc selenide (ZnSe), and titanium dioxide (TiO2).
  • 9. The apparatus of claim 5, wherein the layer of quantum dots comprises a monolayer of quantum dots.
  • 10. The apparatus of claim 5, wherein the quantum dots are suspended in a polymeric material.
  • 11. The apparatus of claim 1, wherein the waveguide comprises: an upper layer which is substantially transparent to the incident light; an active layer comprising the luminescent material, the active layer underlying the upper layer; and a lower layer underlying the active layer which is substantially transparent to the frequency-shifted light; and wherein the diffuse reflector comprises a diffusely reflective layer underlying the lower layer.
  • 12. The apparatus of claim 11, further comprising a selectively reflective layer overlying the upper layer which is substantially transparent to the incident light and selectively reflects the frequency-shifted light.
  • 13. The apparatus of claim 12, wherein the incident light is solar light.
  • 14. The apparatus of claim 13, wherein the frequency-shifted light is red shifted relative to the solar light.
  • 15. The apparatus of claim 12, wherein at least portions of the selectively reflective later and the diffusely reflective layer face each other to form a reflective cavity for the frequency-shifted light.
  • 16. The apparatus of claim 1, further comprising a selective reflector located proximal the waveguide which selectively admits the incident light into the waveguide and which selectively reflects frequency-shifted light from the wave-guide back into the waveguide.
  • 17. The apparatus of claim 12, wherein at least portions of the selective reflector and the diffuse reflector face each other to form a reflective cavity for the frequency-shifted light.
  • 18. The apparatus of claim 16, wherein the selective reflector has a transmissivity of at least 0.9 to incident light and a reflectivity of at least 0.9 to the red shifted light.
  • 19. The apparatus of claim 1, wherein the waveguide is flexible.
  • 20. The apparatus of claim 1, wherein the waveguide comprises a fluid filled shell.
  • 21. The apparatus of claim 20, further comprising a circulator which circulates fluid through the fluid filled shell.
  • 22. The apparatus of claim 21, further comprising a heat exchanger configured to remove heat from the fluid.
  • 23. The apparatus of claim 1, further comprising at lease one heat sink configured to remove heat from the waveguide.
  • 24. The apparatus of claim 23, further comprising a generator configured to generate electrical power from the removed heat.
  • 25. The apparatus of claim 1, further comprising a concentrator which concentrates the incident light onto the waveguide.
  • 26. A method of generating electrical power comprising: obtaining a concentrating apparatus comprising a wave-guide containing a luminescent material which responds to incident light by emitting frequency-shifted light, wherein a first portion of the frequency-shifted light is internally reflected within the wave-guide to a wave-guide output, and a second portion of the frequency-shifted light is transmitted out of the wave-guide; and a diffuse reflector positioned proximal to the waveguide to reflect at least some of the second portion of the frequency-shifted light back in to the waveguide to be internally reflected within the wave-guide to a wave-guide output; positioning a photovoltaic device proximal to the wave-guide output; receiving incident light with the concentrating apparatus to produce frequency-shifted light; and directing at least a portion of the frequency-shifted light to the photovoltaic device to generate electrical power.
  • 27. The method of claim 26, comprising: admitting a portion of the incident light into the waveguide through the selective reflective surface and onto the luminescent material; causing the luminescent material to emit frequency-shifted light in response to the incident light; using the diffuse reflector to reflect a portion of the frequency-shifted light which exits the waveguide back into the waveguide to be internally reflected within the wave-guide to the wave-guide output.
  • 28. The method of claim 27, wherein the incident light is solar light.
  • 29. The method of claim 28, wherein the frequency-shifted light is red shifted relative to the solar light.
  • 30. The method of claim 29, wherein the luminescent material comprises quantum dots.
  • 31. The method of claim 30, wherein the quantum dots comprise particles ranging between about 2 to 10 nanometers in size.
  • 32. The method of claim 30, wherein the quantum dots comprise material selected from the group consisting of cadmium selenide (CdSe) cadmium sulfide (CdS), indium arsenide (InAs), and indium phosphide (InP).
  • 33. The method of claim 30 wherein the quantum dots comprise material selected from the group consisting of lead sulfide (PbS), zinc selenide (ZnSe), and titanium dioxide (TiO2).
  • 34. The method of claim 26, wherein the concentration apparatus further comprises a selective reflector located proximal the waveguide which selectively admits the incident light into the waveguide and which selectively reflects frequency-shifted light from the wave-guide back into the waveguide; and further comprising: admitting a portion of the incident light into the waveguide through the selective reflective surface and onto the luminescent material; causing the luminescent material to emit frequency-shifted light in response to the incident light; using the selective reflector to reflect a portion of the frequency-shifted light which exits the waveguide back into the waveguide to be internally reflected within the wave-guide to the wave-guide output.
  • 35. The method of claim 26, wherein the selective reflector is a diffuse reflector.
  • 36. A system comprising: an apparatus according to any of claim 1; an energy transducer located proximal to the wave guide output to receive frequency shifted light and convert the light to another form of energy.
  • 37. The system of claim 36, wherein the transducer comprises a photovoltaic cell.
  • 38. The system of claim 37, wherein the photovoltaic cell has a higher quantum efficiency in response to the frequency shifted light than in response to the incident light.
  • 39. The system of claim 38, wherein the photovoltaic cell comprises a silicon based solar cell.
  • 40. An apparatus comprising; a wave-guide containing a luminescent material which responds to incident light by emitting frequency-shifted light, and a diffuse reflector positioned proximal to the waveguide to reflect at least some light exiting the waveguide back in to the waveguide to be internally reflected within the wave-guide.
  • 41. The apparatus of claim 40 wherein the at least some light exiting the waveguide comprises frequency-shifted light emitted from the luminescent material.
  • 42. The apparatus of claim 40 wherein the at least some light exiting the waveguide comprises a non-frequency-shifted portion of the incident light.