Transparent energy-harvesting devices

1. An energy harvesting system comprising:

a waveguide including a top surface, a bottom surface, and an edge surface, the waveguide configured to receive sunlight through the top surface, the bottom surface, or both the top surface and the bottom surface;

a luminophore embedded in or disposed on the waveguide, the luminophore being a cyanine or salt thereof, a squarylium, a carbon nanotube, a thiacarbocyanine or salt thereof, a naphthalocyanine or derivative thereof, a phthalocyanine or derivative thereof, a phorphyrin, or a combination thereof; and

a segmented solar photovoltaic array disposed onto a top surface of the waveguide, disposed onto a bottom surface of the waveguide, or embedded within the waveguide,

wherein the energy harvesting system is visibly transparent, having an average visible transmittance of sunlight of greater than about 50% and a color rendering index of sunlight of greater than about 80 referenced to the AM1.5G spectrum at normal incidence to the waveguide.

2. The energy harvesting system according to claim 1 , wherein the luminophore has a strongest peak absorbance of light at a wavelength of greater than about 650 nm and a strongest peak emission of light at a wavelength of greater than about 650 nm.

3. The energy harvesting system according to claim 2 , wherein the luminophore has no peak absorption in the visible spectrum.

4. The energy harvesting system according to claim 2 , wherein the luminophore has a second strongest peak absorbance of light at a wavelength of less than about 450 nm.

5. The energy harvesting system according to claim 1 , comprising a plurality of luminophores, wherein each luminophore of the plurality has a strongest peak emission of light at a wavelength of greater than about 650 nm.

6. The energy harvesting system according to claim 1 , wherein the energy harvesting system has an average visible transmittance of greater than about 70% and a color rendering index of greater than about 85 at normal incidence to the waveguide.

7. The energy harvesting system according to claim 1 , wherein the color rendering index of greater than about 80 is in regard to a reference spectrum of sunlight.

8. The energy harvesting system according to claim 1 , wherein the luminophore has a quantum yield of luminescence of greater than about 20%.

9. The energy harvesting system according to claim 1 , further comprising:

a first wavelength-selective mirror coupled to a first surface of the waveguide, the first wavelength-selective mirror being transparent to visible light and reflective to NIR light; and optionally

a second wavelength-selective mirror coupled to an opposing second surface of the waveguide, the second wavelength-selective mirror being transparent to visible light and reflective to NIR light.

10. The energy harvesting system according to claim 1 , wherein the energy harvesting system is configured as a window for a building, a greenhouse, an automotive vehicle, an aircraft, or a watercraft.

11. The energy harvesting system according to claim 1 , wherein the energy harvesting system is configured as a window for a building and is integrated into the building's electrical system.

12. The energy harvesting system according to claim 1 , wherein the system is integrated into a display on a monitor, a mobile device, or a billboard.

13. A method of constructing a building or an automotive vehicle, the method comprising:

incorporating the light harvesting system according to claim 1 into a building structure to form the building or into an automotive vehicle body to form the automotive vehicle.

14. An energy harvesting system comprising:

a waveguide comprising a visibly transparent glass or plastic, the waveguide including a top surface, a bottom surface, and an edge surface, the waveguide configured to receive sunlight through the top surface, the bottom surface, or both the top surface and the bottom;

a luminophore embedded in or disposed on the waveguide, the luminophore having a strongest peak absorbance of light at a wavelength of greater than about 650 nm, a strongest peak emission of light at a wavelength of greater than about 650 nm, and no peak absorption of light in the visible spectrum, the luminophore being a cyanine or salt thereof, a squarylium, a carbon nanotube, a thiacarbocyanine or salt thereof, a naphthalocyanine or derivative thereof, a phthalocyanine or derivative thereof, a phorphyrin, or a combination; and

a segmented solar photovoltaic array disposed on a top surface of the waveguide, disposed on a bottom surface of the waveguide, or embedded within the waveguide,

wherein the energy harvesting system is visibly transparent, having an average visible transmittance of sunlight of greater than about 50% and a color rendering index of sunlight of greater than about 80 referenced to the AM1.5G spectrum at normal incidence to the waveguide.

15. The energy harvesting system according to claim 14 , wherein the luminophore has a quantum yield of luminescence of greater than about 20%.

16. An energy harvesting system comprising:

a waveguide comprising a visibly transparent glass or plastic;

a luminophore embedded in the waveguide, the luminophore having a strongest peak absorbance of light at a wavelength of greater than about 650 nm, a strongest peak emission of light at a wavelength of greater than about 650 nm, and no peak absorption of light in the visible spectrum, the luminophore being a squarylium, a carbon nanotube, a thiacarbocyanine or salt thereof, a naphthalocyanine or derivative thereof, a phthalocyanine or derivative thereof, or a combination thereof; and

a solar photovoltaic cell coupled to an edge of the waveguide,

wherein the energy harvesting system is visibly transparent, having an average visible transmittance of sunlight of greater than about 50% and a color rendering index of sunlight of greater than about 80 referenced to the AM1.5G spectrum at normal incidence to the waveguide.

17. The energy harvesting system according to claim 1 , wherein the luminophore has a strongest peak absorbance of light at a wavelength of greater than about 650 nm and less than about 1000 nm and the luminophore has a strongest peak emission of light at a wavelength of greater than about 650 nm and less than about 1000 nm.

18. The energy harvesting system according to claim 1 , wherein the average visible transmittance of sunlight is less than 90%.

19. The energy harvesting system according to claim 1 , wherein the luminophore includes a blend of a cyanine or salt thereof and a squarylium.

20. The energy harvesting system according to claim 1 , wherein the luminophore includes a thiacarbocyanine or salt thereof, a naphthalocyanine or derivative thereof, a phthalocyanine or derivative thereof, or a combination thereof.