Solar Cell with Textured Coverglass
A solar cell including a semiconductor body including at least one photoactive junction, and a textured layer or coverglass having a textured surface disposed over the top surface of the semiconductor body. The textured layer may be between 200 and 1800 nm in thickness, and may have a graded index of refraction.
1 . A solar cell comprising:
a semiconductor body including at least one photoactive junction; and
a textured ceria doped glass disposed over the top surface of said semiconductor body.
2 . The solar cell as defined in claim 1 wherein the top surface of the coverglass is textured.
3 . The solar cell as defined in claim 1 wherein the coverglass is approximately 4 mils in thickness and with portion of the glass which is textured is about 200 to 1800 nm in thickness.
4 . The solar cell as defined in claim 1 wherein the top surface of the coverglass is textured so that the incoming light is bent through a plurality of angles so that it is incident upon the surface of the semiconductor body at oblique angles.
5 . The solar cell as defined in claim 1 wherein the top surface of the coverglass is textured in a moth-eye pattern.
6 . The solar cell as defined in claim 1 wherein the top surface of the coverglass is textured in a pattern of polygons of substantially equal dimension.
7 . The solar cell as defined in claim 1 wherein the top surface of the coverglass is textured in a pattern of polygons of different dimension.
8 . The solar cell as defined in claim 1 wherein the top surface of the coverglass is composed of a material having a gradient in the index of refraction from the surface.
9 . The solar cell as defined in claim 8 wherein the gradient in the index of refraction is a plurality of steps.
10 . The solar cell as defined in claim 1 further comprising an antireflection coating deposited over the top surface of the coverglass.
11 . The solar cell as defined in claim 1 wherein the semiconductor body comprises group III-V compound semiconductor elements.
12 . The solar cell as defined in claim 1 wherein the semiconductor body comprises a multijunction solar cell.
13 . A solar cell as defined in claim 1 , wherein the semiconductor body includes a substrate selected from the group consisting of germanium or GaAs.
14 . A multijunction solar cell as defined in claim 12 , wherein the multijunction solar cell includes a first solar subcell is composed of germanium.
15 . A multijunction solar cell as defined in claim 12 , wherein the multijunction solar cell includes a second solar subcell composed of GaAs.
16 . A multijunction solar cell as defined in claim 12 , wherein the multijunction solar cell includes a top solar subcell composed of GaInP.
17 . A solar cell as defined in claim 1 , wherein the coverglass is adhered to the semiconductor body by a substantially transparent adhesive, the adhesive remaining substantially transparent when exposed to an AM0 space environment
18 . A method of manufacturing a solar cell comprising:
providing a semiconductor body including at least one photoactive junction; and
attaching a light refracting coverglass over the top surface of said semiconductor body.
19 . A method as defined in claim 18 , further comprising texturing the top surface of the coverglass to a depth of between 200 and 1800 nm.
20 . A method as defined in claim 18 , further comprising forming a gradient in the index of refraction of top surface of the coverglass at a depth of between 200 and 1800 nm.