Tandem Solar Cell Patents: Leaders, Trends & White Space 2026
- Filing peaked in 2018 at 15 families and has not returned to that level since. the 2022 midpoint sits at just 4 families, and momentum tables show zero recent-year filings across every leading assignee, including LG Electronics and Air Liquide.
- H10K organic-semiconductor claims sit inside 28 of the 82 families. that overlap with perovskite and organic tandem chemistry is worth checking before assuming a silicon-only clearance.
- The United States receives more filings than the rest of the world combined for this search. 37 of 82 records route through the USPTO, with Europe a distant second at 21 and Korea and Australia barely present.
A narrow, slowing field concentrated in silicon-perovskite architecture
The dataset covers 82 patent families filed between 2015 and 2026 that combine tandem or multijunction solar cell language with two-terminal, four-terminal or monolithic tandem architecture claims, narrowed to the semiconductor-device IPC classes that cover junction and cell structure. This is a claims-dense but numerically small corner of photovoltaics: filing activity peaked in 2018 at 15 families and has declined since, with the 2022 midpoint at only 4. Publication lags filing by roughly 18 months, so the most recent years understate true activity, but the multi-year decline through the middle of the trend is not an artefact of that lag alone.
Most of the activity sits inside H01L (semiconductor devices), which covers all 82 families by definition of the search, with a substantial secondary cluster in H10K organic semiconductors. Photovoltaic-specific classification under H02S appears in only 2 records, suggesting most applicants are claiming tandem cell structure through general semiconductor-device language rather than solar-specific classification — a detail worth checking when running freedom-to-operate searches that filter on H02S alone.
Filing trend and technology composition
Two views of the same 82-family dataset: filing activity over time, and how records distribute across the IPC subclasses that define tandem and multijunction cell structure.
A peak in 2018 followed by sustained decline
Filings ran at 12 in 2017 and reached a peak of 15 in 2018. Activity fell through the following years to a 2022 midpoint of 4, and the most recent full year shows no meaningful recovery. Because publication lags filing, the final one or two years on the chart will revise upward, but the shape of the decline predates that lag window.
H01L dominant, H10K a significant secondary cluster
Every record in this set carries an H01L semiconductor-device classification by construction of the search. H10K, covering organic semiconductors including OLED technology, appears in 28 records — a meaningful overlap suggesting organic and perovskite tandem chemistry is claimed alongside conventional junction structure. H01G (capacitors) appears in 14 records, and H02S (photovoltaic-specific classification) in only 2, which is unusually low for a solar-cell dataset and worth noting when scoping searches.
Shares are the percentage of the 82 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Tandem Solar Cell Tandem Cell with Eureka
This page is one run against one query. Ask Eureka your own question about tandem solar cell tandem cell and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited records anchor the field's early architecture
EP3270432A1 — Tandem solar cell and tandem solar cell module
The filing describes a monolithic tandem solar cell built by laminating a perovskite solar cell onto the front surface of a crystalline silicon solar cell, joined through a junction layer. A nano-electrode structure is patterned on the front transparent electrode to manage the optical path of incident light, and the filing covers a manufacturing method alongside the device claims.Filed by LG Electronics, published 2018-01-17.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US4295002A | Heterojunction V-groove multijunction solar cell | 155 |
| 2 | US20170271622A1 | High efficiency thin film tandem solar cells and other semiconductor devices | 39 |
| 3 | JP2018011058A | Tandem solar cell, tandem solar cell module including the same, and manufacturing method thereof | 38 |
| 4 | US20160126401A1 | Tandem photovoltaic device | 38 |
| 5 | US4795501A | Single crystal, heteroepitaxial, GaAlAs/CuInSe2 tandem solar cell and method of manufacture | 36 |
| 6 | US20180158976A1 | Tandem solar cell and method of manufacturing the same | 32 |
| 7 | US20200212243A1 | Method for manufacturing perovskite silicon tandem solar cell | 30 |
| 8 | US4867801A | Triple-junction heteroepitaxial AlGa/CuInSe2 tandem solar cell and method of manufacture | 28 |
| 9 | KR1020180011832A | Tandem solar cell, tanden solar cell module comprising the same and method for manufacturing thereof | 24 |
| 10 | KR1020180007585A | Tandem solar cell, tanden solar cell module comprising the same and method for manufacturing thereof | 21 |
Citation counts favour older records within any searched corpus; treat this table as a map of foundational architecture, not of current commercial relevance.
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Browse MCP servers →What the numbers mean for filing strategy
Three patterns stand out once the dataset is read as decisions rather than counts: where claim density sits, where geography concentrates risk, and where activity has genuinely gone quiet.
The field has cooled since its 2018 peak
Filing density peaked in 2018 and declined steadily through the following years. Recent-year momentum tables show zero filings in the latest year across every leading assignee in the ranking, including LG Electronics and the Air Liquide-linked group. That pattern is consistent with either a maturing claim space or applicants shifting filing strategy toward adjacent classifications not captured by this search.
US filing dominates; Asia-Pacific presence is thin
The United States receives 37 of the 82 records in this dataset, with Europe second at 21 and WIPO PCT filings at 10. South Korea (4) and Australia (1) are minimally represented despite Korean manufacturers appearing among the assignees, suggesting Korean players may be protecting tandem architecture through domestic filings outside this search's classification scope.
Organic and perovskite chemistry claims run through H10K
A third of the dataset classifies under H10K, the organic-semiconductor subclass that also covers OLED technology. This signals that many tandem cell claims are being drafted with organic or perovskite top-cell chemistry in mind rather than purely crystalline-silicon stacks, which matters for anyone scoping a silicon-only clearance search.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to tandem solar cell tandem cell, with the prior art for and against each one.
A fragmented field with no single dominant filer
Across 82 families, recent-year momentum is flat for every named assignee, and the strongest collaboration signal comes from a small cluster of French research and industrial entities rather than a single corporate leader.
LG Electronics holds an early, cited position
LG Electronics' EP3270432A1 filing is among the representative records for monolithic silicon-perovskite tandem structure, but the assignee shows no filings in the most recent year captured, consistent with the broader slowdown across the dataset.
A French research cluster files jointly and repeatedly
The strongest co-assignee links in this dataset connect an Air Liquide-linked research entity with EDF, the CNRS, and the Institut Polytechnique de Paris, each pairing appearing on 5 shared families. That pattern points to a coordinated academic-industrial programme rather than independent parallel filing.
No single assignee dominates the ranking
Beyond the LG and French-cluster filings, the remaining assignees — including Korean and German entities — appear with small, individually modest family counts. This is a field where claim space is occupied piecemeal rather than controlled by one or two large portfolios.
| Assignee | Recent year | YoY |
|---|---|---|
| LG Electronics | 0 | — |
| CHAUDHARI ASHOK | 0 | — |
| L'Air Liquide, Société Anonyme pour l'Étude et l'Exploitation des Procédés Georges Claude | 0 | — |
| Électricité de France (EDF) | 0 | — |
| Centre National de la Recherche Scientifique (CNRS) | 0 | — |
| École Polytechnique (Institut Polytechnique de Paris) | 0 | — |
| INSTITUT PHOTOVOLTA QUE D ILE DE FRANCE (IPVF) | 0 | — |
| Korea Institute of Science and Technology (KIST) | 0 | — |
Where to take this analysis
The dataset points to specific next steps depending on whether the goal is clearance, licensing or R&D scoping.
Run a targeted clearance search on H10K overlap
Any perovskite or organic top-cell design should be checked against the 28 families classified under H10K, not just the H01L core set, before committing to a device architecture.
Explore in EurekaVerify Korean filings outside this classification scope
With only 4 South Korean receiving-office records against a much larger US and European share, Korean manufacturers' tandem portfolios may sit under different classification and warrant a direct KIPO search.
Explore in EurekaTrack whether the 2018 peak was a one-off cycle
The decline from 15 filings in 2018 to 4 at the 2022 midpoint could reflect either claim saturation or a pause ahead of a new filing wave tied to commercial-scale perovskite-silicon production; recent-year data will clarify this as publication catches up.
Explore in EurekaFrequently asked questions
A tandem solar cell stacks two or more photovoltaic junctions with different bandgaps so that each layer absorbs a different part of the solar spectrum, raising theoretical efficiency above what a single-junction silicon cell can reach. The most commercially discussed version pairs a perovskite top cell with a crystalline silicon bottom cell, connected either monolithically in a two-terminal design or mechanically stacked in a four-terminal design. Patent claims in this space cover the junction structure, the interconnect or tunnel layer between sub-cells, and the manufacturing method for bonding the layers together. The architecture choice (two-terminal versus four-terminal) is itself a frequent subject of distinct claim sets.
Across the 82 families in this dataset, no single assignee holds a dominant share. LG Electronics appears with an early, heavily cited monolithic tandem filing, while a cluster of French entities — an Air Liquide-linked research group, EDF, the CNRS and the Institut Polytechnique de Paris — shows the strongest collaborative filing pattern, appearing together on multiple shared families. Korean and German entities also appear in the ranking but with smaller individual counts. The overall picture is a fragmented field rather than one controlled by a small number of large portfolios.
Filing activity in this dataset peaked in 2018 at 15 families and fell to a 2022 midpoint of 4, with recent-year momentum showing no filings from any leading assignee. This could reflect claim space becoming saturated after an initial wave of foundational architecture patents, a shift in applicant strategy toward classifications outside this search's scope, or simply the publication lag that understates the most recent one to two years of activity. It is worth re-running this search periodically as later-filed applications publish and fill in the recent-year gap.
EP3270432A1, filed by LG Electronics, claims a monolithic tandem solar cell in which a perovskite solar cell is laminated onto the front surface of a crystalline silicon solar cell via a junction layer, with a nano-electrode structure patterned on the front transparent electrode to manage the optical path of incident light. It also covers a corresponding manufacturing method. Anyone building a monolithic silicon-perovskite stack with a similar front-electrode patterning approach should review the granted claim scope directly rather than relying on the abstract, since the nano-electrode geometry is the detail most likely to differentiate a design-around from an infringement.
Relative to the dense core claims around monolithic two-terminal architecture, this dataset shows thinner coverage in four-terminal mechanical stacking configurations, tunnel junction interconnect layer chemistry, perovskite top-cell encapsulation methods, and bifacial module integration. The photovoltaic-specific IPC class H02S appears in only 2 of 82 records, which is low for a solar-cell field and suggests some of these branches may be filed under classifications this search did not capture, warranting a supplementary search before concluding the space is genuinely open.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.