US 2012/0055551 A1Published application

Photovoltaic assemblies incorporating an optical element having internal inclusions configured for maximum conversion efficiency

AssigneeE. I. Du Pont de Nemours and Company

InventorsJOSE MANUEL RODRIQUEZ-PARADA, Ronald Jack Riegert, Mark E. Lewittes, Roger Harquail French

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Abstract

A photovoltaic assembly includes an optical element comprising a body having opposed planar major surfaces with a plurality of open-mouthed inclusions (grooves) formed on the light output surface. Each groove has a closed apex with an included apex angle. The body is formed from a material having an index of refraction of at least 1.3 and an induced absorbance rate ΔAbs/Dose less than or equal to about 0.4. The optical element is attached to a photovoltaic cell using an adhesive having an index of refraction in the range from about 1.34 to 1.50. The apex angle is selected such that light incident upon the body is conveyed the light output surface by the mechanism of total internal reflection from the boundary walls of the grooves and/or without retro-reflection toward the incident surface. The thickness of the adhesive layer and the dimension of the mouth of the grooves are selected such that light incident on the surface of the photovoltaic cell is not obscured by conductor lines on the cell's surface.

Claims11

Dependent claims

A photovoltaic assembly comprising:

a photovoltaic cell having a light incident surface and a mounting surface thereon,
an array of conductive lines being disposed over the light incident surface, each conductive line having a predetermined line width substantially equal to a width dimension “g”, adjacent conductive lines in the array being separated from each other by a pitch dimension “p”;
an optical element, the optical element having:
a body having first and second opposed, substantially planar, major surfaces thereon, the first surface defining a light incident surface, the second surface defining a light output surface,
the light output surface having a plurality of grooves formed therein, each groove having a mouth opening on the light output surface, the mouth having a predetermined width dimension “b” measured in the plane of the light output surface,
each groove having opposed, substantially planar boundary walls that extend into the body and terminate therewithin at a closed apex, the closed apex having an included apex angle {acute over (α)},
a layer of an adhesive material having an index of refraction nA disposed between the light output surface of the optical element and the light incident surface of the photovoltaic cell, the layer of adhesive material having an index of refraction nA and having a thickness dimension “t”, the thickness dimension t being such that the adhesive layer covers substantially all of the grid lines of the array,
the optical element being positioned with respect to the photovoltaic cell such that substantially all of the conductive lines on the light incident surface of the cell lie within a respective groove formed on the light output surface of the optical element,
the optical element being improved in that it is operative to collect light incident upon the light incident surface thereof at an incident angle β up to a maximum operating angle βMax measured with respect to a normal to the incident surface and to convey that light to the light output surface without retro-reflection toward the incident surface,
the improved optical element being characterized in that:
the body is formed from a material having an index of refraction nC of at least 1.3 and an induced absorbance rate ΔAbs/Dose less than or equal to about 0.4, and wherein
the index of refraction nA is in the range from about 1.34 to 1.50, and wherein
the angle {acute over (α)} is defined in accordance with the relationship:
α
≤
α
Retro
=
60

°
-
2
3

sin
-
1

(
sin


β
Max
n
C
)
for any maximum operating angle βMax within the range 1°<βMax<90°;
and wherein
the dimension b lies within the range
g
+
2

t


sin


β
Max
n
A
2
-
sin
2

β
Max
=
b
Min
0
<
b
<
b
Max
=
p

70 more elements

A photovoltaic assembly comprising:

a photovoltaic cell having a light incident surface and a mounting surface thereon,
an array of conductive lines being disposed over the light incident surface, each conductive line having a predetermined line width substantially equal to a width dimension “g”, adjacent conductive lines in the array being separated from each other by a pitch dimension “p”;
an optical element, the optical element having:
a body having first and second opposed, substantially planar, major surfaces thereon, the first surface defining a light incident surface, the second surface defining a light output surface,
the light output surface having a plurality of grooves formed therein, each groove having a mouth opening on the light output surface, the mouth having a predetermined width dimension “b” measured in the plane of the light output surface,
each groove having opposed, substantially planar boundary walls that extend into the body and terminate therewithin at a closed apex, the closed apex having an included apex angle {acute over (α)},
a layer of an adhesive material having an index of refraction nA disposed between the light output surface of the optical element and the light incident surface of the photovoltaic cell, the layer of adhesive material having an index of refraction nA and having a thickness dimension “t”, the thickness dimension t being such that the adhesive layer covers substantially all of the grid lines of the array,
the optical element being positioned with respect to the photovoltaic cell such that substantially all of the conductive lines on the light incident surface of the cell lie within a respective groove formed on the light output surface of the optical element,
the optical element being improved in that it is operative to collect light incident upon the light incident surface thereof at an incident angle β up to a maximum operating angle βMax measured with respect to a normal to the incident surface and to convey that light to the light output surface by the mechanism of total internal reflection from the boundary walls of the grooves present within the body of the optical element,
the improved optical element being characterized in that:
the body is formed from a material having an index of refraction nC of at least 1.3 and an induced absorbance rate ΔAbs/Dose less than or equal to about 0.4, and wherein
each groove is filled with a material having an index of refraction nI at least equal to 1, and wherein
the index of refraction nA of the adhesive material is in the range from about 1.34 to 1.50, and wherein
the angle {acute over (α)} is defined in accordance with the relationship:
α
≤
α
TIR
=
2

cos
-
1

(
sin


β
Max
n
C
)
-
2

sin
-
1

(
n
I
n
C
)
for any maximum operating angle βMax chosen from the range
1

°
<
β
Max
<
{
sin
-
1

n
C
2
-
n
I
2
(
n
C
2
-
n
I
2
≤
1
)
90

°
(
n
C
2
-
n
I
2
>
1
)
;
and wherein
the dimension b lies within the range
g
+
2

t


sin


β
Max
n
A
2
-
sin
2

β
Max
=
b
Min
0
<
b
<
b
Max
=
p

124 more elements

A photovoltaic assembly comprising:

a photovoltaic cell having a light incident surface and a mounting surface thereon,
an array of conductive lines being disposed over the light incident surface, each conductive line having a predetermined line width substantially equal to a width dimension “g”, adjacent conductive lines in the array being separated from each other by a pitch dimension “p”;
an optical element, the optical element having:
a body having first and second opposed, substantially planar, major surfaces thereon, the first surface defining a light incident surface, the second surface defining a light output surface,
the light output surface having a plurality of grooves formed therein, each groove having a mouth opening on the light output surface, the mouth having a predetermined width dimension “b” measured in the plane of the light output surface,
each groove having opposed, substantially planar boundary walls that extend into the body and terminate therewithin at a closed apex, the closed apex having an included apex angle {acute over (α)},
a layer of an adhesive material having an index of refraction nA disposed between the light output surface of the optical element and the light incident surface of the photovoltaic cell, the layer of adhesive material having an index of refraction nA and having a thickness dimension “t”, the thickness dimension t being such that the adhesive layer covers substantially all of the grid lines of the array,
the optical element being positioned with respect to the photovoltaic cell such that substantially all of the conductive lines on the light incident surface of the cell lie within a respective groove formed on the light output surface of the optical element,
the optical element being improved in that it is operative to collect light incident upon the light incident surface thereof at an incident angle β up to a maximum operating angle βMax measured with respect to a normal to the incident surface and to convey that light to the light output surface without retro-reflection toward the incident surface and also by the mechanism of total internal reflection from the boundary walls of the grooves present within the body of the optical element,
the improved optical element being characterized in that:
the body is formed from a material having an index of refraction nC of at least 1.3 and an induced absorbance rate ΔAbs/Dose less than or equal to about 0.4, and wherein
each groove is filled with a material having an index of refraction nI at least equal to 1, and wherein
the index of refraction nA of the adhesive material is in the range from about 1.34 to 1.50, and wherein
the angle {acute over (α)} is the smaller of the angles defined in accordance with the following relationships:
α
<
{
α
Retro
=
60

°
-
2
3

sin
-
1

(
sin


β
Max
n
C
)
α
TIR
=
2

cos
-
1

(
sin


β
Max
n
C
)
-
2

sin
-
1

(
n
I
n
C
)
for any maximum operating angle βMax chosen from the smaller of the ranges:
1

°
<
β
Max
<
{
90

°

sin
-
1
n
C
2
-
n
I
2
;
and wherein
the dimension b lies within the range
g
+
2

t


sin


β
Max
n
A
2
-
sin
2

β
Max
=
b
Min
0
<
b
<
b
Max
=
p

126 more elements

A photovoltaic assembly comprising:

a photovoltaic cell having a light incident surface and a mounting surface thereon,
an array of conductive lines being disposed over the light incident surface, each conductive line having a predetermined line width substantially equal to a width dimension “g”, adjacent conductive lines in the array being separated from each other by a pitch dimension “p”;
an optical element, the optical element having:
a body having first and second opposed, substantially planar, major surfaces thereon, the first surface defining a light incident surface, the second surface defining a light output surface,
the light output surface having a plurality of grooves formed therein, each groove having a mouth opening on the light output surface, the mouth having a predetermined width dimension “b” measured in the plane of the light output surface,
each groove having opposed, substantially planar boundary walls that extend into the body and terminate therewithin at a closed apex, the closed apex having an included apex angle {acute over (α)},
a layer of an adhesive material having an index of refraction nA disposed between the light output surface of the optical element and the light incident surface of the photovoltaic cell, the layer of adhesive material having an index of refraction nA and having a thickness dimension “t”, the thickness dimension t being such that the adhesive layer covers substantially all of the grid lines of the array,
the optical element being positioned with respect to the photovoltaic cell such that substantially all of the conductive lines on the light incident surface of the cell lie within a respective groove formed on the light output surface of the optical element,
the optical element being improved in that it is operative to collect light incident upon the light incident surface thereof at an incident angle β up to a maximum operating angle βMax measured with respect to a normal to the incident surface and to convey that light to the light output surface without retro-reflection toward the incident surface,
the improved optical element being characterized in that:
the body is formed from a material having an index of refraction nC of at least 1.3 and an induced absorbance rate ΔAbs/Dose less than or equal to about 0.4, and wherein
the planar boundary walls of the grooves are coated with a reflective material, and wherein
the angle {acute over (α)} is defined in accordance with the relationship:
α
≤
α
Retro
=
60

°
-
2
3

sin
-
1

(
sin


β
Max
n
C
)
for any maximum operating angle βMax within the range 1°<βMax<90°;
and wherein
the dimension b lies within the range
g
+
2

t


sin


β
Max
n
A
2
-
sin
2

β
Max
=
b
Min
0
<
b
<
b
Max
=
p

70 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/180,638Filed 12 Jul 2011
Priority: 13 Jul 2010
Published: 8 Mar 2012
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H10F 77/484
Directly associated or integrated with photovoltaic cells, e.g. light-reflecting means or light-concentrating means: refractive…
H02S 40/22
Optical components: light-reflecting or light-concentrating means
H10F 19/80
Integrated devices, or assemblies of multiple devices, comprising at least one photovoltaic cell covered by group H10F10/00, e.g. photovoltaic…
H10F 77/488
Directly associated or integrated with photovoltaic cells, e.g. light-reflecting means or light-concentrating means: reflecting…

Family

Application61/363,758Us provisional application · filed 13 Jul 2010
Application61/363,764Us provisional application · filed 13 Jul 2010
Application61/363,769Us provisional application · filed 13 Jul 2010
Application61/363,773Us provisional application · filed 13 Jul 2010
Application61/363,784Us provisional application · filed 13 Jul 2010
Application61/373,778Us provisional application · filed 13 Aug 2010
Application61/502,469Us provisional application · filed 29 Jun 2011
Application61/502,479Us provisional application · filed 29 Jun 2011
Application61/502,498Us provisional application · filed 29 Jun 2011
Application61/502,506Us provisional application · filed 29 Jun 2011
US 8,648,248 B2Related patent
US 2012/0055551 A1This patent

From the US filing history. Foreign family members aren’t listed.