Solar Cells with Built-in Bypass Switches
This patent describes how to build a solar cell with a bypass switch directly into the same piece of silicon, making solar panels more efficient and reliable.
Original patent title: “Systems and methods for monolithically integrated bypass switches in photovoltaic solar cells and modules”
This patent describes how to build a solar cell with a bypass switch directly into the same piece of silicon, making solar panels more efficient and reliable. Granted to Solexel in 2015 with 39 claims and 3 forward citations, and it is expected to expire in 2033.
Coverage
What does this patent actually cover?
This patent details a way to create a solar cell and a bypass switch together on a single piece of semiconductor material, like silicon. The solar cell part captures sunlight to make electricity. A special trench, or divider, separates the solar cell from a bypass switch region. This bypass switch, which can be a type of diode or transistor, is designed to activate if the solar cell gets shaded or damaged. When activated, it lets electricity flow around the faulty cell, preventing it from overheating or causing problems for the whole panel. The patent describes how metal layers on the front and back, along with conductive plugs through an insulating backplane, connect these components. For example, if one cell in a panel is shaded, its bypass switch turns on, allowing current from other cells to pass through it without being blocked.
The gap
What does this patent NOT cover?
- Solar cells where the bypass switch is a separate component added later.
- Solar panels that do not use a trench to isolate the solar cell and bypass switch regions.
- Bypass switches that are not monolithically integrated (built into the same structure) with the solar cell.
- Solar cells made from materials other than silicon, such as thin-film compounds, unless they are also monolithic structures with bypass switches.
- Bypass switches that are not designed as diodes or transistors.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The innovation lies in integrating the bypass switch directly into the same silicon wafer as the solar cell, using a trench for isolation and multiple metal layers for connections. This 'monolithic' approach reduces manufacturing complexity and improves reliability compared to adding separate bypass diodes.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Modern solar panels with integrated bypass diodes
Flexible solar modules using monolithic cell designs
Why it matters
The bigger picture
Solar panels are made of many cells connected together. If one cell is shaded or fails, it can act like a bottleneck, reducing the power output of the entire panel and potentially overheating. Integrating bypass switches directly into each cell, as described in this patent, is a key method to mitigate these issues, improving the overall performance and longevity of solar modules.
Filed
October 16, 2013
Granted
December 22, 2015
Market context
Who's building on this
Companies in this space
Companies involved in solar cell manufacturing, such as those producing high-efficiency photovoltaic modules, likely implement or licenselicensePermission from the patent owner to make, use, or sell the invention — usually in exchange for payment. Doesn't transfer ownership.Read more → technologies based on this integrated bypass switch concept. While Solexel was an early player, the principles are now widely adopted across the industry.
Market impact
The integration of bypass switches directly into solar cells has become a standard feature in many commercial solar modules. This design improvement helps to increase energy yield, especially in partially shaded conditions, and enhances the reliability and safety of solar installations, contributing to the widespread adoption of solar energy.
Claim 1 — Plain English
What this patent covers
This patent details a way to create a solar cell and a bypass switch together on a single piece of semiconductor material, like silicon. The solar cell part captures sunlight to make electricity. A special trench, or divider, separates the solar cell from a bypass switch region. This bypass switch, which can be a type of diode or transistor, is designed to activate if the solar cell gets shaded or damaged. When activated, it lets electricity flow around the faulty cell, preventing it from overheating or causing problems for the whole panel. The patent describes how metal layers on the front and back, along with conductive plugs through an insulating backplane, connect these components. For example, if one cell in a panel is shaded, its bypass switch turns on, allowing current from other cells to pass through it without being blocked.
The clever bit
The innovation lies in integrating the bypass switch directly into the same silicon wafer as the solar cell, using a trench for isolation and multiple metal layers for connections. This 'monolithic' approach reduces manufacturing complexity and improves reliability compared to adding separate bypass diodes.
What it does not cover
- Solar cells where the bypass switch is a separate component added later.
- Solar panels that do not use a trench to isolate the solar cell and bypass switch regions.
- Bypass switches that are not monolithically integrated (built into the same structure) with the solar cell.
- Solar cells made from materials other than silicon, such as thin-film compounds, unless they are also monolithic structures with bypass switches.
- Bypass switches that are not designed as diodes or transistors.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
PatentBrief Score
Impact Score
Early stage
Citation count
12/40
Early citations
Claim breadth
20/20
Very broad protection
Recency
5/20
Granted 10–20 years ago
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$63K – $202K
Midpoint $126K · 7.0 yr remaining · industry ×1.5
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
The original legal language
Original claims
39 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Moslehi, M. M. (2015). Solar Cells with Built-in Bypass Switches (U.S. Patent No. 9,219,171). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/9219171/systems-and-methods-for-monolithically-integrated-bypass-switches-in-photovoltai
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does Solar Cells with Built-in Bypass Switches cover?
This patent describes how to build a solar cell with a bypass switch directly into the same piece of silicon, making solar panels more efficient and reliable.
Who owns patent US 9219171?
Solexel owns this patent, granted in 2015.
When does this patent expire?
This patent is expected to expire on October 16, 2033, when the invention enters the public domain.
What is patent US 9219171 cited by?
This patent has been cited by 3 later patents that build on its ideas.
What problem does this patent solve?
Solar panels are made of many cells connected together. If one cell is shaded or fails, it can act like a bottleneck, reducing the power output of the entire panel and potentially overheating. Integrating bypass switches directly into each cell, as described in this patent, is a key method to mitigate these issues, improving the overall performance and longevity of solar modules.
What does this patent NOT cover?
Solar cells where the bypass switch is a separate component added later.
Same assignee
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