PHOTOVOLTAIC DEVICES WITH CONDUCTING LAYER INTERCONNECTS
According to the embodiments provided herein, a photovoltaic device can have one or more cells with a conducting layer interconnect.
1 . A photovoltaic cell of a photovoltaic device comprising:
a first conducting layer and a second conducting layer over a semiconductor stack comprising an absorber layer, wherein the first conducting layer has an average conducting layer thickness;
a dielectric layer positioned between the first conducting layer and the second conducting layer, wherein the dielectric layer has an average dielectric layer thickness; and
a conducting layer interconnect that extends from the second conducting layer and through the dielectric layer, wherein:
the conducting layer interconnect forms an electrical connection with a contact region of the first conducting layer,
the contact region of the first conducting layer has a flat and annular shape, and
a ratio of the average dielectric thickness to the average conducting layer thickness is at least 10:1.
2 . The photovoltaic cell of claim 1 , wherein:
the first conducting layer has a maximum thickness,
the contact region of the first conducting layer has a surface area, and
a ratio of the maximum thickness of the first conducting layer to the surface area of the contact region is at least 750:1.
3 . The photovoltaic cell of claim 1 , wherein:
the conducting layer interconnect is bounded by a via wall of the dielectric layer,
an interface angle θ is defined by the via wall of the dielectric layer and the contact region of the first conducting layer,
and the interface angle θ is larger than 75°.
4 . The photovoltaic cell of claim 1 , wherein the conducting layer interconnect directly contacts the semiconductor stack.
5 . The photovoltaic cell of claim 1 , wherein:
the semiconductor stack comprises a back contact layer over the absorber layer, and
the first conducting layer is over the back contact layer.
6 . The photovoltaic cell of claim 1 , wherein a thickness of the first conducting layer is less than 3 μm.
7 . The photovoltaic cell of claim 1 , wherein the first conducting layer comprises one or more layers of metal, one or one or more layers of nitrogen-containing metal, or both.
8 . The photovoltaic cell of claim 1 , wherein the second conducting layer comprises one or more layers of metal, one or one or more layers of nitrogen-containing metal, or both.
9 . The photovoltaic cell of claim 1 , wherein the dielectric layer has greater than 10% transmissivity to wavelengths between 300 nm and 1,100 nm.
10 . The photovoltaic cell of claim 1 , wherein the first conducting layer and the second conducting layer have a different material composition.
11 . A method for forming a photovoltaic device comprising:
forming a first conducting layer over a semiconductor stack, wherein the first conducting layer has a conducting layer thickness;
forming a dielectric layer over the first conducting layer, wherein the dielectric layer has a dielectric layer thickness;
heating an affected region of the first conducting layer with a laser pulse;
melting, at least partially, the affected region of the first conducting layer, whereby a contact region is formed in the first conducting layer and a portion of the dielectric layer disposed over the affected region of the first conducting layer is delaminated to define a via through the portion of the dielectric layer, wherein a ratio of the dielectric layer thickness to the conducting layer thickness is at least 10:1; and
forming a conducting layer interconnect through the via of the dielectric layer and in contact with the contact region of the first conducting layer.
12 . The method of claim 11 , wherein the conducting layer interconnect is formed by depositing a second conducting layer over the dielectric layer.
13 . The method of claim 11 , wherein the dielectric layer has greater than 10% transmissivity to the laser pulse.
14 . The method of claim 11 , wherein the laser pulse has a Gaussian shaped relative intensity.
15 . The method of claim 11 , wherein the laser pulse has a pulse width of less than 5,000 ps.
16 - 18 . (canceled)
19 . The method of claim 11 , wherein:
the first conducting layer has a maximum thickness,
the contact region of the first conducting layer has a surface area, and
a ratio of the maximum thickness of the first conducting layer to the surface area of the contact region is at least 750:1.
20 . The method of claim 11 , wherein:
the conducting layer interconnect is bounded by a via wall of the dielectric layer,
an interface angle θ is defined by the via wall of the dielectric layer and the contact region of the first conducting layer,
and the interface angle θ is larger than 75°.
21 . (canceled)
22 . The method of claim 11 , wherein:
the semiconductor stack comprises a back contact over the absorber layer, and
the first conducting layer is over the back contact layer.
23 . (canceled)
24 . The method of claim 11 , wherein a thickness of the first conducting layer is between about 50 nm to about 2.5 μm.
25 - 27 . (canceled)
28 . The method of claim 11 , wherein the first conducting layer and the second conducting layer have a different material composition.