Shingled solar cells overlapping along non-linear edges
Solar devices and methods for producing solar devices are disclosed. In some examples, a solar device includes solar cells arranged in a shingled manner such that adjacent long edges of adjacent ones of the solar cells overlap. The adjacent long edges have a non-linear shape that has protruding portions. The solar device includes contact pads arranged in the protruding portions of the adjacent long edges such that the contact pads of the adjacent ones of the solar cells are electrically connected.
1. A solar device comprising:
a plurality of solar cells each including a substantially planar front surface and a substantially planar rear surface having two opposing long edges extending in a length direction between respective ends of two opposing short edges that extend in a width direction, the plurality of solar cells being arranged in a shingled manner such that adjacent long edges of an adjacent pair of the solar cells overlap, wherein
a first long edge of a first solar cell of the plurality of solar cells has a non-linear shape including protruding portions and includes contact pads arranged in peaks of the protruding portions on the rear surface of the first solar cell,
a second long edge of a second solar cell of the plurality of solar cells has a non-linear shape including protruding portions and contact pads arranged in peaks of the protruding portions on the front surface of the second solar cell,
wherein the first long edge and the second long edge are adjacent and overlap to form an overlapping region such that the contact pads on the rear surface of the first long edge of the first solar cell cover and electrically connect to the contact pads on the front surface of the second long edge of the second solar cell and such that the overlapping region in the width direction is larger at the contact pads than at point between the contact pads.
2. The solar device of claim 1 , wherein the non-linear shape of the first long edge or the non-linear shape of the second long edge is a sinusoidal pattern.
3. The solar device of claim 1 , wherein the solar device comprises a top solar cell, a bottom solar cell, and a plurality of interior solar cells, and wherein each interior solar cell includes a top non-linear edge following a repeating pattern and a bottom undulated edge following the repeating pattern offset from the top non-linear edge to mirror the first repeating pattern.
4. The solar device of claim 1 , comprising:
a sacrificial solar cell overlapping the front surface of an end one of the adjacent solar cells and conductively bonded to the front surface of the end one of the adjacent solar cells to electrically and mechanically connect the rear surface of the sacrificial solar cell in series with the adjacent solar cells;
a first conductive lead conductively bonded to the rear surface of a solar cell located at an opposite end of the solar device from the sacrificial solar cell, the first conductive lead configured to provide, during operation of the solar device, a first electrical output from the solar device having a first polarity; and
a second conductive lead conductively bonded to the rear surface of the sacrificial solar cell and configured to provide, during operation of the solar device, a second electrical output from the solar device having a second polarity opposite from the first polarity;
wherein the sacrificial cell is configured, by virtue of the second conductive lead being conductively bonded to the rear surface of the sacrificial solar cell, to contribute no power to a module-level electrical output of the solar device during operation of the solar device.
5. The solar device of claim 1 , comprising a plurality of conductive busbars, wherein each conductive busbar extends along a respective adjacent long edge and electrically connects a row of contact pads arranged along the respective adjacent long edge, and wherein each conductive busbar has a width that varies along a respective adjacent long edge such that the conductive busbar is fully underneath an overlapping region of an adjacent one of the solar cells.
6. A solar cell comprising:
a top non-linear edge extending in a length direction and following a first pattern including protruding portions;
a bottom non-linear edge extending in the length direction and following a second pattern that mirrors the first pattern such that the second pattern includes protruding portions;
two opposing short edges that extend in a width direction between respective ends of the top and bottom non-linear edges;
a back side and a front side configured, by a semiconductor diode structure, to generate an electric current in response to light shining on the front side; and
contact pads positioned only in peaks of the protruding portions of the top non-linear edge on the front side of the solar cell and in the bottom non-linear edge on the back side of the solar cell such that the solar cell does not include contact pads along the two opposing short edges.
7. A method of assembly a solar cell device, comprising:
dividing a photovoltaic wafer into a plurality of solar cells each having a substantially planar front surface and a substantially planar rear surface having two opposing long edges extending in a length direction between respective ends of two opposing short edges that extend in a width direction, a first long edge of a first solar cell of the plurality of solar cells having a non-linear shape including protruding portions, and a second long edge of a second solar cell of the plurality of solar cells having a non-linear shape including protruding portions;
disposing contact pads along the first long edge in peaks of the protruding portions on the rear surface of the first solar cell;
disposing contact pads along the second long edge in peaks of the protruding portions on the front surface of the second solar cell of the plurality of solar cells; and
assembling the solar cells in a shingled manner so that the first long edge and the second long edge are adjacent and overlap to form an overlapping region such that the contact pads on the rear surface of the first solar cell cover and electrically connect to the contact pads on the front surface of the second long edge of the second solar cell and such that the overlapping region in the width direction is larger at the contact pads than at points between the contact pads.
8. The method of claim 7 , wherein dividing the photovoltaic wafer comprises scribing the photovoltaic wafer to create a plurality of non-linear scribe lines and cleaving the photovoltaic wafer along the non-linear scribe lines.
9. The method of claim 8 , wherein scribing the photovoltaic wafer comprises creating the non-linear scribe lines so that each non-linear scribe line alternatingly extends between a direction towards a top edge of the solar device and a direction towards a bottom edge of the solar device in a repeating pattern.
10. The method of claim 9 , wherein creating the non-linear scribe lines comprises following a sinusoidal pattern with a laser scribe machine.
11. The method of claim 10 , wherein following the sinusoidal pattern with the laser scribe machine comprises alternating, between each non-linear scribe line, between a first sinusoidal pattern and a second sinusoidal pattern that mirrors the first sinusoidal pattern.
12. The method of claim 10 , wherein disposing the contact pads comprises alternatingly disposing each contact pad between a plurality of peaks and a plurality of troughs of a respective non-linear scribe line following the sinusoidal pattern.
13. The method of claim 7 , wherein assembling the solar cells in a shingled manner comprises picking and placing, by a robot, the solar cells and rotating, by the robot, every other solar cell by 180 degrees.
14. The method of claim 7 , wherein assembling the solar cells in a shingled manner comprises picking and placing, by a first robot, every other solar cell into the solar device and picking and placing, by a second robot, the remaining solar cells into another solar device.
15. The method of claim 7 , comprising adding to the solar device:
a sacrificial solar cell overlapping the front surface of an end one of the adjacent solar cells and conductively bonded to the front surface of the end one of the adjacent solar cells to electrically and mechanically connect the rear surface of the sacrificial solar cell in series with the adjacent solar cells;
a first conductive lead conductively bonded to the rear surface of a solar cell located at an opposite end of the solar device from the sacrificial solar cell, the first conductive lead configured to provide, during operation of the solar device, a first electrical output from the solar device having a first polarity; and
a second conductive lead conductively bonded to the rear surface of the sacrificial solar cell and configured to provide, during operation of the solar device, a second electrical output from the solar device having a second polarity opposite from the first polarity;
wherein the sacrificial cell is configured, by virtue of the second conductive lead being conductively bonded to the rear surface of the sacrificial solar cell, to contribute no power to a module-level electrical output of the solar device during operation of the solar device.
16. The method of claim 7 , comprising disposing a plurality of conductive busbars such that each conductive busbar electrically connects a row of contact pads arranged along the respective adjacent long edge, wherein each conductive busbar has a width that varies along a respective adjacent long edge such that the conductive busbar is fully underneath an overlapping region of an adjacent one of the solar cells.