Solar cell module

1. A solar cell module, comprising:

a plurality of solar cells;

a concentration unit arranged at a position spaced apart from the plurality of solar cells, a first side of the concentration unit forming a flat surface configured to receive incident solar light, and a second side of the concentration unit facing a direction opposite the first side and towards the plurality of solar cells, the concentration unit configured to concentrate the incident solar light and output concentrated solar light from the second side; and

a reflection unit arranged at a position spaced apart from the second side of the concentration unit, the reflection unit configured to face the second side of the concentration unit and to reflect, towards the second side of the concentration unit and through spaces defined between the plurality of solar cells, light that is incident upon the reflection unit,

wherein the second side of the concentration unit is provided with a reflective region that faces the reflection unit and the plurality of solar cells and that is configured to trap, in an air gap defined between the concentration unit and the reflection unit, at least a portion of the concentrated solar light that is output from the second side of the concentration unit,

wherein the concentration unit comprises a plurality of lenses arranged at the second side of the concentration unit, each of the plurality of lenses having a convex shape toward the plurality of solar cells,

wherein the reflective region on the second side of the concentration unit covers at least a part of the plurality of lenses, extends along the convex shape of each of the plurality of lenses, and defines a plurality of slits that are disposed at a lower end portion of each the plurality of lenses and that are configured to output the concentrated solar light,

wherein the reflective region on the second side of the concentration unit is configured to:

concentrate the incident solar light that is incident on the first side of the concentration unit and output the concentrated solar light from the second side of the concentration unit, and

re-reflect the light that is reflected by the reflection unit and that is incident on the second side of the concentration unit,

wherein the air gap defined between the concentration unit and the reflection unit is formed as an empty space without a filling agent,

wherein the solar cell module further comprises a sealing member that is disposed along edges of the concentration unit and along edges of the reflection unit and that is configured to seal the air gap defined between the concentration unit and the reflection unit,

wherein the sealing member extends from the concentration unit and is attached to the reflection unit, and

wherein the sealing member comprises a first sealing member facing opposite to the air gap, and a second sealing member disposed between the air gap and the first sealing member.

2. The module of claim 1 , wherein an aggregate area of the plurality of slits on the reflective region is 0.1% to 5% of an area of the flat surface of the concentration unit.

3. The module of claim 1 , wherein each of the plurality of lenses in the concentration unit corresponds to a respective one of the plurality of slits on the reflective region on the second side of the concentration unit, and each lens is provided with a recess that is recessed away from the respective slit and toward the flat surface on the first side of the concentration unit.

4. The module of claim 1 , wherein the plurality of slits on the reflective region of the concentration unit are filled with a light-transmissive material.

5. The module of claim 1 , wherein the plurality of lenses in the concentration unit are arranged with each of the plurality of lenses extending lengthwise along a first direction and the plurality of lenses being sequentially arranged along a second direction perpendicular to the first direction.

6. The module of claim 1 , wherein the plurality of lenses are arranged adjacent to each other, and a filling member is arranged between adjacent lenses among the plurality of lenses to fill at least part of a gap formed between the adjacent lenses among the plurality of lenses.

7. The module of claim 1 , wherein the concentration unit comprises a plurality of materials having different refractive indexes.

8. The module of claim 7 , wherein the second side of the concentration unit comprises a flat surface, the concentration unit is a flat lens configured to concentrate light by the different refractive indexes of the plurality of materials in the concentration unit, and the reflective region is provided on the flat surface of the second side of the concentration unit.

9. The module of claim 7 , wherein the different refractive indexes of the plurality of materials in the concentration unit are in a range of 1.2 to 3.4.

10. The module of claim 1 , wherein the reflection unit that is arranged at the position spaced apart from the second side of the concentration unit comprises:

a base substrate; and

at least one reflection board arranged to cover the base substrate.

11. The module of claim 10 , wherein the plurality of solar cells are mounted on a first surface of the base substrate and the at least one reflection board is disposed on the first surface.

12. The module of claim 10 , wherein the at least one reflection board comprises:

first reflection boards that are arranged on the base substrate; and

second reflection boards that are disposed, together with the plurality of solar cells, between the base substrate and the concentration unit.

13. The module of claim 10 , wherein each of the at least one reflection board is provided with a plurality of protrusions.

14. The module of claim 1 , further comprising spacers that are disposed between the concentration unit and the reflection unit and that are configured to maintain the empty space between the concentration unit and the reflection unit.

15. The module of claim 1 , wherein the reflection unit is coated with a wavelength converting material configured to convert a wavelength of infrared light into a wavelength of visible light.

16. The module of claim 1 , wherein the reflective region faces and contacts an outer surface of each of the plurality of lenses.

17. The module of claim 1 , wherein the first sealing member is made of thermoplastic starch, silicon, or thermoplastic elastomer, and

wherein the second sealing member is made of polyisobutylene.