Photovoltaic cells having micro-embossed optical enhancing structures

• US 5,782,993 A
• Filed: 06/28/1996
• Issued: 07/21/1998
• Est. Priority Date: 06/28/1996
• Status: Expired due to Fees

• Current Assignee: Jackie Ponewash
• Original Assignee: Jackie Ponewash
• Inventors: Ponewash, Jackie
• Primary Examiner(s): NGUYEN, NAM X
• Application Number:
  US08/671,768
• Time in Patent Office: 753 Days
• Field of Search: 136/246, 136/257, 136/259, 136/256, 136/245
• US Class Current: 136/251
• CPC Class Codes: H01L 31/048 Encapsulation of modules
• 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: Y02E 10/52 PV systems with concentrators

Abstract

A photovoltaic device has micro-embossed optical enhancing structures formed on an inner surface of a transparent polymer film material which is laminated to the light incident surface of a photovoltaic cell. Preferably, the micro-embossed structures are in the form of an array of holographic pyramid structures which are interconnected by a series of light channels that are also embossed on the inner surface of transparent film material. In another embodiment, the photovoltaic device is comprised of a layer of flexible transparent polymer material, such as polyester, and a layer of flexible base substrate, preferably of a polymer film, between which are disposed at least one layer of amorphous silicon and at least one layer of metalization forming a photovoltaic cell. By utilizing a pair of flexible sheets of polymer material as the outer layers of the photovoltaic device, the device is deformable in at least one orientation other than a plane defining the sheets of polymer film material.

Claims

1. A photovoltaic device comprising:

a photovoltaic cell having at least one light incident surface; and

a layer of transparent polymer film material having a plurality of optical enhancing structures micro-embossed on an inner surface thereof which is layered in optical connection with the light incident surface of photovoltaic cell.

2. The photovoltaic device of claim 1 wherein the optical enhancing structure comprise:

a grid of holographic pyramidal structures; and

a plurality of channel structures interconnecting multiple ones of the pyramidal structures.

3. The photovoltaic device of claim 2 wherein the pyramidal structures include a flat top and four sides, each of the sides forming a concave surface comprised of a pair of equilateral triangles.

4. The photovoltaic device of claim 1 wherein each of the optical enhancing structures occupies no more than 1 mm² of surface area of the transparent polymer film.

5. The photovoltaic device of claim 1 wherein the transparent polymer film is a transparent polyester.