LIGHT TRAPPING OPTICAL COVER

• US 20140158199A1
• Filed: 02/14/2014
• Published: 06/12/2014
• Est. Priority Date: 04/21/2009
• Status: Active Grant

• Current Assignee: SVV Technology Innovations, Inc.
• Original Assignee: Sergiy Victorovich Vasylyev
• Inventors: Vasylyev, Sergiy
• Granted Patent: US 9,678,321 B2
• Time in Patent Office: Days
• US Class Current: 136/259
• CPC Class Codes: G02B 3/005 arranged along a single direction only, e.g. lenticular sheets G02B3/0043 takes precedence
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: H01L 31/054 Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means
• CPC Class Codes: H01L 31/0543 comprising light concentrating means of the refractive type, e.g. lenses
• CPC Class Codes: H01L 31/0547 comprising light concentrating means of the reflecting type, e.g. parabolic mirrors, concentrators using total internal reflection
• CPC Class Codes: H01L 31/056 the light-reflecting means being of the back surface reflector [BSR] type
• CPC Class Codes: H02S 40/22 Light-reflecting or light-concentrating means directly associated with the PV cell or integrated with the PV cell H01L31/054
• CPC Class Codes: Y02E 10/52 PV systems with concentrators

Abstract

A light trapping optical cover employing an optically transparent layer with a plurality of light deflecting elements. The transparent layer is configured for an unimpeded light passage through its body and has a broad light input surface and an opposing broad light output surface. The light deflecting elements deflect light incident into the transparent layer at a sufficiently high bend angle with respect to a surface normal and direct the deflected light toward a light harvesting device adjacent to the light output surface. The deflected light is retained by means of at least TIR in the system formed by the optical cover and the light harvesting device which allows for longer light propagation paths through the photoabsorptive layer of the device and for an improved light absorption. The optical cover may further employ a focusing array of light collectors being pairwise associated with the respective light deflecting elements.

Claims

1. An optical cover for use in an immediately adjacent position to a top surface of a light harvesting device, comprising:

a layer of optically transmissive material including a plurality of discrete light deflecting means spaced apart from each other,

wherein each of the plurality of light deflecting means is configured to alter the transversal propagation direction of light incident onto said light harvesting device and communicate said light a generally greater propagation angle with respect to a surface normal than a pre-defined critical angle.

2. An optical cover as recited in claim 1, wherein said predefined critical angle is an angle of a total internal reflection characterizing at least one surface of said layer.

3. An optical cover as recited in claim 1, wherein each of said light deflecting means comprises at least one reflective surface inclined at an angle to a surface of said layer.

4. An optical cover as recited in claim 1, wherein each of said light deflecting means comprises at least one refractive surface inclined at an angle to a surface of said layer.

5. An optical cover as recited in claim 1, wherein each of said light deflecting means comprises a surface configured to reflect light by means of a total internal reflection.

6. An optical cover as recited in claim 1, wherein each of said light deflecting means comprises a surface relief feature.

7. An optical cover as recited in claim 1, wherein each of said light deflecting means is selected from the group consisting of prismatic grooves, prismatic cavities, pyramidal cavities, conical cavities, cavities having a high aspect ratio, blind holes, through holes, surface discontinuities, surface corrugations, planar mirrors, curved mirrors, mirror arrays, prisms, prism arrays, one or more reflective or refractive surfaces, undercuts, notches, discontinuities in said layer, diffraction gratings, holograms, surface texture, light diffusing elements, and light scattering elements.

8. An optical cover as recited in claim 1, wherein each of said light deflecting means has an elongated shape and is aligned generally parallel to a reference line.

9. An optical cover as recited in claim 1, wherein said plurality of light deflecting means is arranged in a cylindrical configuration.

10. An optical cover as recited in claim 1, wherein said plurality of light deflecting means is arranged in an axisymmetrical configuration.

11. An optical cover as recited in claim 1, further comprising a plurality of light collecting elements optically coupled to said light deflecting means so that each pair of an individual light collecting element and an individual light deflecting means forms an individual opticule configured as a two-stage optical system in which said light collecting element collects light from its input aperture and focuses said light onto said deflecting means having a generally smaller aperture and configured to redirect the focused beam at a different angle compared to the incidence angle.

12. An optical cover as recited in claim 1, further comprising a micro-lens array disposed in optical communication with said plurality of light deflecting means.

13. An optical cover as recited in claim 1, further comprising a micro-lens array disposed in optical communication with said plurality of light deflecting means, wherein said lens array includes micro-lenses in either one of the cylindrical or point focus configuration.

14. An optical cover as recited in claim 1, further comprising one or more optical cladding layers having a lesser refractive index than said layer of optically transmissive material.

15. An optical cover as recited in claim 1, wherein said light harvesting device comprises a layer of photovoltaic material.

16. An optical cover as recited in claim 1, wherein said light harvesting device comprises a layer of photovoltaic material and a layer of electroconductive transparent material.

17. An optical cover as recited in claim 1, wherein said light harvesting device comprises a layer of photovoltaic material and a grid of electroconductive contacts.

18. An optical cover as recited in claim 1, wherein said light harvesting device comprises a reflective surface.

19. An optical cover as recited in claim 1, wherein said light harvesting device comprises one or more devices selected from the group consisting of solar cells or panels, radiation detectors, light absorbers, photo-chemical reactors and photo-bioreactors.

20. An optical cover for use in an immediately adjacent position to a major surface of a generally planar photoabsorptive layer, comprising:

a layer of optically transmissive material configured to transmit incident light into said photoabsorptive layer and direct at least a substantial portion of the incident light to said photoabsorptive layer at such an angle with respect to a surface normal that results in trapping said portion of the incident light within said photoabsorptive layer by means of at least a total internal reflection.