US-12622125-B2 - Integrated bypass diode schemes for solar modules

Abstract

Hybrid solar cell plates with integrated bypass diodes and modules thereof are described. In an embodiment, a hybrid solar cell plate includes a step surface including a floor and a step edge extending from the floor and across a thickness of a top subcell. A bypass diode is over the floor and laterally adjacent to the step edge.

Inventors

• Giles EPERON
• Emmanuel Van Kerschaver

Assignees

• Swift Solar Inc.

Dates

Publication Date

20260505

Application Date

20241017

Claims (19)

1. 1 . A hybrid solar cell plate comprising: a bottom electrode layer; a top subcell over the bottom electrode layer; a step surface including a floor and a step edge extending from the floor and across a thickness of the top subcell; a bypass diode spanning over the floor and the top subcell; and a patterned metal layer spanning over the bypass diode, wherein the patterned metal layer comprises a plurality of metal finger electrodes spanning over the top subcell.
2. 2 . The hybrid solar cell plate of claim 1 , wherein the patterned metal layer comprises a metal busbar substantially located over the floor.
3. 3 . The hybrid solar cell plate of claim 2 , wherein the bypass diode is characterized by a finger and busbar pattern underlying a portion of the plurality of metal finger electrodes and the metal busbar.
4. 4 . The hybrid solar cell plate of claim 1 , wherein: the step edge is adjacent to and parallel to a peripheral edge of the hybrid solar cell plate; the top subcell is a portion of an only solar cell of the hybrid solar cell plate; and the bypass diode is an only bypass diode of the hybrid solar cell plate.
5. 5 . The hybrid solar cell plate of claim 1 , further comprising a bottom subcell, wherein: the top subcell comprises: a first bottom junction layer of a first carrier type; and a first top junction layer of a second carrier type opposite the first carrier type; and the bottom subcell comprises: a second bottom junction layer of the first carrier type; and a second top junction layer of the second carrier type opposite the first carrier type.
6. 6 . The hybrid solar cell plate of claim 5 , wherein the step edge extends across a thickness of the second top junction layer.
7. 7 . The hybrid solar cell plate of claim 6 , wherein the floor spans over the first bottom junction layer.
8. 8 . The hybrid solar cell plate of claim 6 , further comprising a bottom bypass electrode on the floor, wherein the bypass diode spans over the bottom bypass electrode.
9. 9 . The hybrid solar cell plate of claim 8 , wherein the bottom bypass electrode fills a substantial height of the step edge of the step surface.
10. 10 . The hybrid solar cell plate of claim 9 , further comprising an insulator material that fills a gap laterally between the top subcell and the bottom bypass electrode.
11. 11 . The hybrid solar cell plate of claim 5 , wherein: the second bottom junction layer is p-doped silicon; the first bottom junction layer is a hole transport layer; the first top junction layer is an electron transport layer; and further comprising a perovskite absorber layer between the first bottom junction layer and the first top junction layer.
12. 12 . The hybrid solar cell plate of claim 1 , further comprising a top transparent electrode layer.
13. 13 . A hybrid solar cell plate comprising: a bottom electrode layer; a top subcell over the bottom electrode layer; a top transparent electrode layer over the top subcell; a step surface including a floor and a step edge extending from the floor and across a thickness of the top subcell and the top transparent electrode layer; a bypass diode spanning over the floor and the top subcell; and a patterned metal layer spanning over the bypass diode.
14. 14 . The hybrid solar cell plate of claim 13 , wherein the patterned metal layer spans over the bypass diode and the top transparent electrode layer.
15. 15 . The hybrid solar cell plate of claim 14 , wherein the patterned metal layer includes a plurality of metal finger electrodes spanning over the top subcell.
16. 16 . The hybrid solar cell plate of claim 15 , wherein the patterned metal layer includes a metal busbar substantially located over the floor.
17. 17 . A solar module comprising: a first hybrid solar cell plate comprising: a first bottom electrode layer; a first top subcell over the first bottom electrode layer; a first step surface including a first floor and a first step edge extending from the first floor across a first thickness of the first top subcell; a first bypass diode spanning over the first floor and the first top subcell; and a first patterned metal layer spanning over the first bypass diode, wherein the first patterned metal layer comprises a first plurality of first metal finger electrodes spanning over the first top subcell; and a second hybrid solar cell plate comprising: a second bottom electrode layer; a second top subcell over the second bottom electrode layer; a second step surface including a second floor and a second step edge extending from the second floor across a second thickness of the second top subcell; a second bypass diode over the second floor and the second top subcell; and a second patterned metal layer spanning over the second bypass diode; wherein the first patterned metal layer is connected to the second bottom electrode layer, wherein the second patterned metal layer comprises a second plurality of second metal finger electrodes spanning over the second top subcell.
18. 18 . The solar module of claim 17 , wherein the first patterned metal layer is connected to the second bottom electrode layer with a ribbon or wiring.
19. 19 . The solar module of claim 17 , wherein the first patterned metal layer is connected to the second bottom electrode layer with a conductive film, conductive paste, or solder.

Description

RELATED APPLICATIONS This application is a divisional of co-pending U.S. application Ser. No. 18/145,819 filed Dec. 22, 2022, which is incorporated herein by reference. BACKGROUND Field Embodiments described herein relate to solar cells, and more particularly to integration of bypass diodes for solar modules. Background Information Photovoltaic cells, also referred to solar cells, are devices that convert radiant photo energy into electrical energy. Multiple solar cells may be integrated into a group to constitute a solar panel, or module, in which the solar cells are usually connected in series creating an additive voltage. Reverse bypass diodes may be included in some implementations to provide operational stability to a photovoltaic module. For example, shading of a solar cell wired in series within a string of solar cells can force the cell into reverse bias, causing hot-spot heating which may lead to detrimental effects such as cracking, shorting, or delamination. A bypass diode can limit the reverse bias voltage a shaded solar cell experiences, thus preventing the creation of such hot-spots. Conventional silicon solar cells are connected and placed into modules in two main ways. In a first implementation full or half cells are connected by soldering wires or flat busbar ribbons to the front of the solar cell, and specifically to screen printed metal fingers. The attached busbar is longer than the cell and can make contact to the back of the next cell in a series connection. In another implementation smaller cells are connected in series through a process in which the top of one cell is placed under the next cell and so on, allowing the positive terminal of one cell to contact the negative terminal of the next cell, or vice versa depending on the type of solar cell used. Bypass diodes may generally be soldered into a photovoltaic array during module layup and packaging. For a silicon solar cell array, only a few bypass diodes are required to ensure operational stability and prevent damage from hot-spots because of the high reverse bias breakdown voltage of silicon solar cells. Specifically, the bypass diodes are added at the edge of the photovoltaic module and connected in parallel to a string, or strings, of solar cells, with an opposite polarity to the solar cells. If one or more of the solar cells in a serially connected string is shaded, they could be put in reverse bias. In this case, the bypass diode that is wired in parallel to the string is put into forward bias to allow the flow of current over some threshold voltage, essentially allowing current to flow around the string including the shaded solar cell(s). SUMMARY Hybrid solar cell plates and modules thereof are described in which the hybrid solar cell plates include solar cells with integrated bypass diodes. In an embodiment, a hybrid solar cell plate includes a bottom electrode layer, a top electrode layer, and a top subcell between the bottom electrode layer and the top electrode layer. The top subcell may include a first bottom junction layer of a first carrier type (e.g. hole or electron), and a first top junction layer of a second carrier type (e.g. hole or electron) opposite the first carrier type. The hybrid solar cell plate additionally includes a step surface including a floor and a step edge extending from the floor and across a thickness of the top subcell. In accordance with embodiments, a bypass diode is over the floor and laterally adjacent to the step edge. An insulator material or air gap may be located laterally between the bypass diode and the top subcell to prevent shorting. The step surface in accordance with embodiments may assume a variety of configurations, including a trench within the top subcell or ledge. In accordance with embodiments, the bottom electrode layer spans underneath the bypass diode (and floor) to make back side electrical connection with both the solar cell and bypass diode of the hybrid solar cell plate. Top side electrical connection may include a plurality of metal finger electrodes spanning over the top subcell and a metal busbar substantially located over the floor of the step surface. In this manner, the step surface can both accommodate the bypass diode and provide an area over which the metal busbar can be located without blocking light transmission to the top subcell. In accordance with embodiments, the step edge is adjacent to and parallel to a peripheral edge of the hybrid solar cell plate, which can facilitate serial connection, the top subcell is portion of an only solar cell of the hybrid solar cell plate, and the bypass diode is an only bypass diode of the hybrid solar cell plate. The hybrid solar cell plates in accordance with embodiments can be fabricated with single junction (single subcell) and multiple junction (multiple subcell) solar cells, and with various geometries and polarities. In various tandem solar cell stack-ups the hybrid solar cell plate can additionally include a bot