Free-standing two-sided device fabrication
View Patent ↗Solar cells attached to a contact lens are provided, as well as methods for making the solar cells and contact lenses. The solar cells have electrodes on only one side of the device, which facilitates attachment of the solar cell to a contact lens. In one embodiment, the solar cells are made using a “two sided” process. By using the two-sided process, solar cells of only a few microns in thickness can be fabricated. Such relatively thin solar cells can be incorporated into a contact lens without discomfort to the wearer. By providing an infinitely renewable power source on a contact lens, the solar cells enable the use of electronic components on the contact lens while eliminating the recharging or replacing issues that arise with batteries.
1. A powered contact lens, comprising a transparent substrate having a plurality of recesses shaped to be worn directly over a user's eye, a photovoltaic component disposed in one of the plurality of recesses, and an electronic component disposed in another of the plurality of recesses, wherein the photovoltaic component is in electronic communication with the electronic component, and wherein the photovoltaic component has a p contact and an n contact on only a first side of the photovoltaic component.
2. The contact lens of claim 1 , wherein the p contact and the n contact are coplanar.
3. The contact lens of claim 1 , wherein the photovoltaic component has a thickness of 50 microns or less.
4. The contact lens of claim 1 , wherein the photovoltaic component has a thickness of 10 microns or less.
5. The contact lens of claim 1 , further comprising a plurality of photovoltaic components, wherein each of the plurality of photovoltaic components are disposed in a corresponding one of the plurality of recesses.
6. The contact lens of claim 5 , further comprising an interconnect network disposed on the transparent substrate and electronically connecting the plurality of photovoltaic components and the electronic component.
7. The contact lens of claim 5 , wherein at least two of the plurality of photovoltaic components are electronically connected in series.
8. The contact lens of claim 5 , wherein at least two of the plurality of photovoltaic components are electronically connected in parallel.
9. The contact lens of claim 1 , wherein the transparent substrate is a polymer substrate.
10. The contact lens of claim 1 , wherein the photovoltaic component comprises a silicon p/n junction.
11. The contact lens of claim 1 , wherein the photovoltaic component is embedded in the transparent substrate.
12. The contact lens of claim 11 , wherein the photovoltaic component is enclosed within the substrate.
13. The contact lens of claim 11 , further comprising an encapsulation layer overlying the substrate and abutting a second side of the photovoltaic component, which is opposite the first side of the photovoltaic component.
14. The contact lens of claim 13 , wherein the encapsulation layer is a conformal layer that covers the entire contact lens.