CIGS Solar Cell Passivation Layer Patents: Trends & White Space 2026
- 214 families, one peak year. Filings rose from 7 in 2017 to a peak of 21 in 2018, then eased back toward flat by 2022 — this is a field that already had its filing surge.
- China leads filing by a wide margin. 82 of the tracked records were filed in China, ahead of the United States (45) and South Korea (43), showing where production and IP protection are concentrated together.
- Claims sit almost entirely at the device level. All 214 records classify under H01L, while coating-process (C23C) and system-integration (H02S) classifications carry only a handful of filings each — the process and integration layers are comparatively open.
What this landscape covers
This landscape tracks 214 patent families filed between 2015 and 2026 that combine CIGS thin-film solar cell terminology with rear-passivation, point-contact and buffer-layer claim language, classified under the core photovoltaic device IPC codes. It captures the structural work on how a passivation or buffer layer is positioned relative to the back contact and absorber layer, not general CIGS manufacturing.
Filing activity peaked in 2018 and has flattened since, with China, the United States and South Korea as the three leading receiving offices. Classification is heavily concentrated in semiconductor-device claims, leaving coating-process and system-integration branches comparatively thin.
How CIGS passivation filings have moved since 2017
Filing volume, geography and technology classification for the 214 patent families tracked in this dataset, spanning rear passivation, point-contact structures and CdS-free buffer layers on CIGS cells.
Filing trend: a 2018 peak, then a flattening curve
Filings rose from 7 in 2017 to a peak of 21 in 2018, then eased toward 8 by the 2022 midpoint. The most recent years are undercounted because publication typically lags filing by around 18 months, but the trajectory through the mid-2020s is flat to declining rather than accelerating.
Classification: concentrated in semiconductor devices, thin elsewhere
All 214 records classify under H01L (semiconductor devices), with much smaller clusters in H10P, C23C (coating and surface deposition), C01B (inorganic compounds), H02S (photovoltaic power generation) and a handful of records in C09D, B23K and C04B — evidence that the field is claimed almost entirely at the device-structure level rather than at the process-chemistry or system-integration level.
Shares are the percentage of the 214 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on CIGS Solar Cell Passivation Layer with Eureka
This page is one run against one query. Ask Eureka your own question about cigs solar cell passivation layer and every answer comes back with the patent numbers behind it.
Try EurekaThe records anchoring this landscape
CIS/CIGS solar cell with a rear TCO layer and manufacturing method
The filing discloses a CIS/CIGS solar cell built from a substrate carrying two spaced molybdenum electrodes, with a transparent conductive oxide (TCO) layer wrapped over the upper and lateral faces of the second electrode. A buffer layer sits over the TCO to compensate for the bandgap mismatch between the TCO and the light-absorbing layer, which is itself deposited across the first electrode, the buffer and the exposed substrate area between them.Filed by Korea Institute of Energy Research, published 2014-10-01.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20120199203A1 | Glass sheet for cu-in-ga-se solar cells, and solar cells using same | 96 |
| 2 | WO2009137637A2 | Nanoparticles and methods of making and using | 52 |
| 3 | US20100319776A1 | Ink for forming thin film of solar cells and method for preparing the same, CIGS thin film solar cell using t… | 22 |
| 4 | US20160336475A1 | Hexagonal phase epitaxial cadmium sulfide on copper indium gallium selenide for a photovoltaic junction | 21 |
| 5 | CN103077980A | 一种铜铟镓硒薄膜太阳能电池及其制备方法 | 20 |
| 6 | KR1020090123645A | High-efficiency CIGS solar cells and manufacturing method thereof | 20 |
| 7 | EP2040305A2 | Ink for forming thin film for solar cells and method for preparing the same, CIGS thin film solar cell using … | 20 |
| 8 | CN102779891A | 铜铟镓硒薄膜型太阳能电池装置及其制备方法 | 18 |
| 9 | US20120227811A1 | Electrochemical method of producing copper indium gallium diselenide (CIGS) solar cells | 18 |
| 10 | US20090242022A1 | Solar Cell | 16 |
Ranked by citation count within this dataset; older filings accumulate more citations by virtue of time in the corpus, not necessarily current commercial weight.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. Each row carries its publication number; clicking a row searches Eureka by that number.
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Three read-outs from the trend, classification and citation data that matter more for a filing decision than the raw counts alone.
The surge already happened
Filing activity peaked in 2018 and had eased to 8 by the 2022 midpoint, moving toward zero by the most recent tracked year. Recent years are understated because publication lags filing by roughly 18 months, but the direction is clearly flattening rather than accelerating.
Structure is claimed, process is not
Every record in this dataset classifies under H01L (semiconductor devices), while coating-and-deposition methods (C23C, 18 records) and inorganic-compound chemistry (C01B, 6 records) are represented far more thinly, despite governing how a passivation layer is actually manufactured.
Influence sits with a few older filings
The most-cited record in this corpus, on cover-glass compatibility for Cu-In-Ga-Se cells, carries 96 citations — well ahead of the next-most-cited records. High citation counts favour older filings simply by virtue of time in the corpus, so treat this as a marker of influence rather than of current commercial relevance.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to cigs solar cell passivation layer, with the prior art for and against each one.
Who is filing, and where momentum has stalled
Filing in this dataset is spread across South Korean research institutes, Chinese solar manufacturers and Japanese electronics firms, with no single filer showing sustained recent-year activity.
Momentum has stalled across the board
Every assignee tracked for recent-year momentum in this dataset — spanning Japanese, Korean and Chinese organisations — shows zero filings in the most recent tracked year. That is consistent with the broader flattening trend rather than specific to any one filer.
Collaboration is rare and concentrated
Only three co-assignee pairs appear in the dataset. The strongest links a Hong Kong university with a Chinese Academy of Sciences institute, and a Beijing photovoltaic firm with a US university and a US national laboratory — cross-border academic-industry pairing rather than competitor-to-competitor filing.
Three offices carry most of the volume
China, the United States and South Korea together account for the large majority of receiving-office activity, with Europe and PCT filings each in the mid-teens. Filing location tracks closely with where CIGS manufacturing capacity and demand are concentrated.
| Assignee | Recent year | YoY |
|---|---|---|
| Nitto Denko Corporation | 0 | — |
| Beijing Dingrong Photovoltaic Technology Co., Ltd. | 0 | — |
| Korea Institute of Energy Research | 0 | — |
| Electronics and Telecommunications Research Institute (ETRI) | 0 | — |
| The 18th Research Institute of China Electronics Technology Group Corporation | 0 | — |
| Korea Advanced Institute of Science and Technology (KAIST) | 0 | — |
| Weike Co., Ltd. | 0 | — |
| The Chinese University of Hong Kong | 0 | — |
Where to take this analysis next
The filing trend and classification data point to specific follow-up checks before committing R&D or filing budget to this space.
Pressure-test the under-claimed branches
Coating-process and system-integration classifications carry a fraction of the volume of the core device claims. Run a freedom-to-operate check on the specific process-parameter or integration claim you have in mind before assuming the space is open.
Run a white space search in EurekaTrack the assignees still active near the cut-off
Recent-year momentum has dropped to zero across the assignees tracked here. Confirm which, if any, have continuation or later-family filings not yet published, since publication lag means the true recent picture is incomplete.
Monitor assignee activity in EurekaRead the top-cited filings directly
The highest-cited records in this corpus define the structural claims most other filings had to work around. Reading them in full is a faster way to scope a design-around than working from citation counts alone.
Open the citation network in EurekaCommon questions about CIGS passivation layer patents
A passivation layer sits at the rear or point-contact interface of a copper indium gallium selenide (CIGS) cell to reduce recombination losses and improve open-circuit voltage. It is patented separately from the overall cell structure because the layer's composition, deposition sequence and contact geometry are each independently patentable improvements that can be licensed or claimed without covering the whole device. This dataset shows filings classified specifically under IPC codes for buffer layers and point-contact passivation, distinct from the broader CIGS cell classification.
Filing in this dataset is fragmented rather than dominated by one company: South Korean research institutes, Chinese solar equipment makers and Japanese electronics firms all appear among the assignees, alongside university research groups. No single filer shows sustained recent-year momentum in this dataset — several previously active assignees show zero filings in the most recent tracked year, consistent with the overall flattening filing trend. Reviewing the assignee ranking table directly is more reliable than any single summary statement here.
Yes, but at a lower volume than the peak year of 2018. CdS-free buffer chemistries remain represented in the dataset through South Korean and Chinese institutional filings, reflecting continued interest in avoiding cadmium sulfide for environmental and processing reasons. The overall filing trend across the whole passivation-layer field is flat to declining by the 2022 midpoint, so treat any single sub-branch's activity as part of that broader slowdown rather than as an independent growth signal.
The clearest white space sits outside the dominant H01L semiconductor-device classification: coating and deposition process claims (C23C) and inorganic-compound chemistry claims (C01B) carry a small fraction of the filing volume that device-structure claims do. Photovoltaic system-integration claims (H02S) are similarly thin. These branches are mechanically connected to how a passivation layer is made and deployed but are under-claimed relative to the structural claims that dominate the corpus, which is where a narrowly scoped process or integration claim is more likely to clear prior art.
China leads with 82 records in this dataset, followed by the United States at 45 and South Korea at 43. The European Patent Office and WIPO's PCT route each show 14 records, with a smaller number filed directly in India. That distribution indicates manufacturers are prioritising protection in the major CIGS production and demand markets rather than pursuing broad multi-jurisdiction coverage through PCT alone.
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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.