Photovoltaics with interferometric ribbon masks

• US 8,193,441 B2
• Filed: 12/17/2008
• Issued: 06/05/2012
• Est. Priority Date: 12/17/2007
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Kothari, Manish, Khazeni, Kasra
• Primary Examiner(s): Michener, Jennifer
• Assistant Examiner(s): Slawski, Magali P
• Application Number:
  US12/336,865
• Publication Number:
  US 20090151771A1
• Time in Patent Office: 1,266 Days
• Field of Search: 359/380, 359/389
• US Class Current: 136/244
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02B 5/284 of etalon type comprising a resonant cavity other than a thin solid film, e.g. gas, air, solid plates etalons for fibre optic multiplexing G02B6/29358; etalons for spectral measurement G01J3/26
• CPC Class Codes: H01L 31/02168 the coatings being antireflective or having enhancing optical properties for the solar cells
• CPC Class Codes: H01L 31/022425 for solar cells
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

An interferometric mask covering a reflective conductive ribbon that electrically interconnects a plurality of photovoltaic cells is disclosed. Such an interferometric mask may reduce reflections of incident light from the conductors. In various embodiments, the mask reduces reflections, so that a front and back electrode pattern appears black or similar in color to surrounding features of the device. In other embodiments, the mask may modulate reflections of light such that the electrode pattern matches a color in the visible spectrum.

Claims

1. A method of interconnecting a plurality of photovoltaic cells, comprising:

aligning a ribbon conductor along a plurality of photovoltaic cells, wherein the ribbon conductor includes a conductive layer, an optical resonant cavity over the conductive layer, and an absorber layer over the optical resonant cavity, wherein the absorber layer includes a semitransparent thickness of a metallic or semiconductor layer, and wherein the optical resonant cavity and the absorber layers are configured to reduce a percentage of reflectivity of the conductive layer to less than about 10 percent; and

attaching the ribbon conductor along the plurality of photovoltaic cells such that the ribbon conductor is operatively coupled to the photovoltaic cells and the photovoltaic cells are electrically interconnected.

2. The method of claim 1, further including providing the ribbon conductor with stress-relief bends.

3. The method of claim 1, wherein attaching the ribbon conductor includes using an adhesive layer.

4. The method of claim 3, wherein the adhesive layer includes solder.

5. The method of claim 1, wherein the photovoltaic cells have a plurality of at least one of front electrodes, back electrodes, and contacts.

6. The method of claim 5, wherein the ribbon conductor connects the plurality of at least one of the front electrodes, back electrodes, and contacts through insulating material.

7. The method of claim 1, wherein the optical resonant cavity layer and the absorber layer are made of a conductive material.

8. The method of claim 1, wherein the optical resonant cavity layer and the absorber layer are configured such that a color of light reflected from the conductor substantially matches a color of surrounding features on the photovoltaic device.

9. The method of claim 1, wherein the optical resonant cavity layer and the absorber layer are configured such that little or no incident visible light is reflected from the conductor such that the ribbon appears black from a normal viewing angle.

10. The method of claim 1, wherein the optical resonant cavity layer and the absorber layer are configured such that the reflectivity in the visible range from the conductor is less than 5%.

11. A system for converting optical energy to electrical energy comprising:

a plurality of photovoltaic cells;

a conductor electrically connecting the plurality of photovoltaic cells;

the conductor including a conductor layer and an optical interferometric modulator mask over the conductor layer,

wherein the mask includes an optical resonant cavity over the conductor layer, and an absorber layer over the optical resonant cavity, wherein the absorber layer includes a semitransparent thickness of a metallic or semiconductor layer; and

wherein the mask is configured to mask reflections from the conductor layer to less than about 10 percent.

12. The system of claim 11, further including an adhesive material configured for joining the conductor layer and optical interferometric modulator mask with the plurality of photovoltaic cells.

13. The system of claim 12, wherein the adhesive material includes solder.

14. The system of claim 11, wherein the optical interferometric modulator mask is configured to appear black.

15. The system of claim 11, wherein the optical interferometric modulator mask is configured to reduce visible reflectivity over the conductor layer to less than 5%.

16. The system of claim 11, wherein the optical interferometric modulator mask further includes a reflective mirror layer between the optical resonant cavity and the conductor layer.

17. The system of claim 11, wherein the optical resonant cavity includes a dielectric layer.

18. The system of claim 11, wherein the optical resonant cavity includes an optically transparent conductive layer.

19. The system of claim 11, wherein the optical resonant cavity includes a plurality of layers.

20. The system of claim 11, wherein the optical resonant cavity is disposed along both a front side and a back side of the conductor layer such that the optical resonant cavity substantially surrounds the conductor layer.

21. The system of claim 11, wherein the metallic material is selected from the group consisting of Cr, Mo, MoCr, and Ti.