SHJ a-Si:H / TCO Materials Patent Landscape 2026
The SHJ a-Si:H and TCO materials patent field is moderately concentrated, with the top five filers holding 28% of the hundred largest filers’ combined records and France’s CEA leading the ranking. The field is past its 2021 activity peak, though publication lag means the most recent two years are under-counted.
CEA leads a moderately concentrated field anchored in China
The French Atomic Energy Commission (CEA) holds the top position with 27 patent records, followed by Jiangxi State Power Investment New Energy Technology with 19 and IBM with 15. The top-ranked applicant’s share is meaningful but not dominant, indicating room for challengers.
The top five filers account for 28% of the hundred largest filers’ combined records — a moderate concentration level. There is a visible tier gap between the leader (27 records) and the mid-tier cluster around 5–9 records, suggesting the field is not locked up by a single incumbent but lacks a close rival to CEA.
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 1 | French Alternative Energies and Atomic Energy Commission (CEA) | 27 | |
| 2 | Jiangxi State Power Investment New Energy Technology Co., Ltd. | 19 | |
| 3 | IBM (International Business Machines Corporation) | 15 | |
| 4 | 3SUN SRL | 13 | |
| 5 | Suzhou Aikang Low Carbon Technology Institute | 12 | |
| 6 | Tongwei Solar (Jintang) Co., Ltd. | 9 | |
| 7 | SHANGHAI INST OF MICROSYSTEM & INFORMATION TECH CH… | 8 | |
| 8 | Tongwei Solar Energy (Chengdu) Co., Ltd. | 8 | |
| 9 | École Polytechnique Fédérale de Lausanne (EPFL) | 7 | |
| 10 | Zhejiang Akcome Optoelectronic Technology Co., Ltd. | 7 |
| # | Applicant | Patent records | Share |
|---|---|---|---|
| 11 | State Power Investment New Energy Technology (Longgang) Co., Ltd. | 7 | |
| 12 | ENN Solar Energy Co., Ltd. | 6 | |
| 13 | Jinneng Photovoltaic Technology Co., Ltd. | 6 | |
| 14 | Tongwei Solar (Anhui) Co., Ltd. | 5 | |
| 15 | Tongwei Solar (Hefei) Co., Ltd. | 5 | |
| 16 | Tongwei Solar Energy (Meishan) Co., Ltd. | 5 | |
| 17 | KU Leuven (Katholieke Universiteit Leuven) | 5 | |
| 18 | imec (Interuniversity Microelectronics Centre) | 5 | |
| 19 | LONGi Green Energy Technology Co., Ltd. | 5 | |
| 20 | Shanghai Jiao Tong University | 4 |
CEA’s long-standing lead, built on silicon heterojunction device architecture and thin-film passivation, sets a high prior-art baseline. Challengers entering from the Chinese manufacturing base — notably Tongwei Solar entities and Jiangxi SPIC — are filing heavily in device-process integration, which could close the gap if momentum is sustained.
Filings from 2024–2026 are subject to publication lag and will likely increase as pending applications publish; no conclusions about structural decline should be drawn from those years alone. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
Annual volume eased from a 2021 peak; H01L dominates the technology mix
Two charts frame the field’s dynamics: a year-by-year filing trend from 2017 onward and a breakdown of IPC technology branches. Together they confirm a maturing, device-centric field that peaked in 2021 and has a thin footprint in process and materials sub-classes.
Annual filing trend
Annual filings rose to a peak of 31 records in 2021, then eased. The 2024 figure of 12 and the near-zero 2025–2026 counts reflect publication lag, not a structural collapse; treat those years as under-counted. The multi-year recent-window growth is negative at -16%, consistent with a field that has passed its inflection point.
↗ Hover for values · click a bar to ask EurekaTechnology composition
H01L (semiconductor devices) accounts for the large majority of records, reflecting the device-centric nature of SHJ cell innovation. Adjacent branches — nanotechnology (B82Y), coating and deposition (C23C), electroplating (C25D), and organic semiconductors (H10K) — each carry only single-digit record counts, signalling that materials-process and nano-engineering sub-spaces remain lightly patented.
↗ Hover for values · click a bar to ask EurekaHighly cited patent families surfaced by the query
Citation-heavy patent families returned by the query. Use this section as citation context, not as a curated list of the most topic-specific patents.
HOCHEFFIZIENTE SILIZIUM-SOLARZELLE MIT HETEROÜBERG…
The present application discloses a high-efficiency silicon heterojunction (HJT) solar cell and a manufacturing method thereof, and belongs to the technical field of solar cells. In the solar cell of the present application, an N-type crystal silicon wafer is successively provided with a thin SiO2 layer, a hydrogenated amorphous carbon silicon oxide film… (excerpt from the patent abstract)
| # | Patent | Citations |
|---|---|---|
| 1 | 双面受光的晶体硅/薄膜硅异质结太阳电池及制作方法 | 43 |
| 2 | 一种钙钛矿/硅异质结太阳能叠层电池结构及其制作方法 | 40 |
| 3 | Silicon heterojunction solar cells and methods of … | 35 |
| 4 | 一种高效硅异质结太阳能电池及其制备方法 | 22 |
| 5 | 硅异质结太阳电池及其制备方法 | 22 |
| 6 | 一种硅异质结太阳电池本征钝化层的结构及其制作方法 | 21 |
| 7 | 非晶硅－晶体硅异质结太阳电池 | 20 |
| 8 | 硅异质结太阳能电池以及制造方法 | 19 |
Ranked by total forward citations. Citation counts favour older and broadly cited patent families, and broad or adjacent patents may appear when they match the search scope. Treat this section as citation context, not as a curated list of the most topic-specific patents. Some patent titles may be shown in their original, non-English language where an accurate translation could not be guaranteed.
What the patent structure means for R&D investment decisions
Four dimensions — maturity, concentration, collaboration, and geography — shape the strategic context for engineers deciding where to allocate resources in SHJ a-Si: H and TCO materials.
Past-peak field with consolidating core
The lifecycle stage is Decline: annual filings have eased back from the 2021 peak of 31 records, and the recent-window growth rate is –16%. The field is not collapsing — it reflects a consolidating, commercially active technology. New entrants should expect dense prior art in mainstream device architecture and look to adjacent process or materials angles for differentiation.
Lifecycle: DeclineModerate concentration with a clear leader tier gap
The top five filers hold 28% of the hundred largest filers’ combined records — a moderate level that leaves meaningful space for challengers. However, a tier gap exists between CEA at 27 records and the next cluster below 20, meaning any challenger must build a sizeable portfolio to credibly contest the leader’s prior-art position. IBM’s 15-record presence introduces a cross-sector dimension through its nanotechnology-linked filings.
Moderate concentrationCEA–3SUN and intra-Tongwei pairings dominate co-filing
The strongest co-filing link is between CEA and 3SUN SRL, sharing 13 joint records — the most active collaboration in the corpus. Tongwei Solar’s four Chinese subsidiaries form a dense internal co-filing cluster of 5 records each, signalling coordinated portfolio strategy. State Power Investment Corporation Research Institute and Jiangxi SPIC co-filed 4 records, and Akcome’s Jiangsu and Zhejiang entities collaborate on 3. These clusters indicate that cross-entity alignment — either corporate-group or public-private — is the primary collaboration model in this field.
Cross-border & intra-groupChina dominates prosecution; Europe and US are secondary
China accounts for the largest share of patent records filed in this corpus, with the United States, European Patent Office, and PCT as secondary routes. India and Australia show small but non-trivial presences, suggesting some filers are beginning to build out manufacturing-market coverage. Japan and South Korea carry only 2 records each, notable given those countries’ historical strength in thin-film PV, and may represent a prosecution gap worth monitoring.
China-led, global secondaryGo beyond the landscape: Eureka’s TRIZ Solution agent breaks down an R&D problem and returns patented concept solutions, each with a technical approach and cited patent & literature evidence.
| Applicant | Collaborator | Co-filings |
|---|---|---|
| French Alternative Energies and Atomic Energy Commission (CEA) | 3SUN SRL | 13 |
| Tongwei Solar (Jintang) Co., Ltd. | Tongwei Solar Energy (Meishan) Co., Ltd. | 5 |
| Tongwei Solar (Jintang) Co., Ltd. | Tongwei Solar Energy (Chengdu) Co., Ltd. | 5 |
| Tongwei Solar (Jintang) Co., Ltd. | Tongwei Solar (Anhui) Co., Ltd. | 5 |
| Tongwei Solar (Jintang) Co., Ltd. | Tongwei Solar (Hefei) Co., Ltd. | 5 |
| State Power Investment Corporation Research Institute Co., Ltd. | Jiangxi State Power Investment New Energy Technology Co., Ltd. | 4 |
| Jiangsu Akcome Energy Research Institute Co., Ltd. | Zhejiang Akcome New Energy Technology Co., Ltd. | 3 |
| French Alternative Energies and Atomic Energy Commission (CEA) | ENN Solar Energy Co., Ltd. | 2 |
| Jiangsu Akcome Energy Research Institute Co., Ltd. | Zhejiang Akcome Future Technology Co., Ltd. | 2 |
| Jiangsu Akcome Energy Research Institute Co., Ltd. | Zhejiang Akcome Optoelectronic Technology Co., Ltd. | 2 |
Co-filing pairs, ranked by the number of jointly-filed patent families.
CEA leads on volume; Jiangxi SPIC is the fastest-rising challenger
The leader and primary challenger occupy very different trajectories: CEA’s output is declining from a high base, while Jiangxi State Power Investment New Energy Technology is a new entrant posting 8 recent records with strong momentum.
Commissariat à l’Énergie Atomique (CEA)
CEA holds 27 patent records, the largest portfolio in this corpus, focused entirely on H01L semiconductor device classes — specifically H01L 31, H01L 27, and H01L 51 — reflecting deep coverage of heterojunction device architecture and thin-film stack design. Its collaboration with 3SUN SRL (13 joint records) extends its reach into industrial cell manufacturing. However, its recent momentum shows a sharp –86% decline versus its prior filing rate, indicating the institute has largely completed its foundational filing campaign in this space.
patent records: 27Jiangxi State Power Investment New Energy Technology Co., Ltd.
With 19 patent records and a new-entrant trajectory, Jiangxi SPIC is the fastest-rising filer in the corpus. Its technology focus spans H01L 31 (11 records) and reaches into B23K welding/soldering and C25D electroplating, signalling interest in cell interconnection and metallization processes that go beyond pure thin-film passivation. The co-filing relationship with State Power Investment Corporation Research Institute (4 joint records) suggests a coordinated group-level push into HJT manufacturing.
patent records: 19| Applicant | Recent (3 yrs) | Trend |
|---|---|---|
| French Alternative Energies and Atomic Energy Commission (CEA) | 2 | ▼ -86% |
| State Power Investment Corporation Research Institute Co., Ltd. | 1 | ▲ new entrant |
| 3SUN SRL | 2 | ▼ -82% |
| Jiangsu Akcome Energy Research Institute Co., Ltd. | 2 | ▲ new entrant |
| Jiangxi State Power Investment New Energy Technology Co., Ltd. | 8 | ▲ new entrant |
| Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences | 1 | ▲ new entrant |
Coating deposition and nanotechnology are lightly patented adjacent areas
Several IPC branches adjacent to the dominant H01L core carry very few records relative to the overall corpus, marking them as under-served. Two carry plausible technical relevance to SHJ cell performance improvement.
C23C · Coating & Surface Deposition
C23C (coating and surface deposition) carries only 6 patent records — roughly 2% of the branch-level count. For SHJ cells, TCO deposition by sputtering or CVD is a direct process step, yet the prior-art density here is thin. An entrant with novel low-damage deposition methods for ITO or IZO layers could occupy meaningful white space. The realistic entry path is process-focused claims on deposition parameters, target materials, or in-line monitoring, distinct from the device-level claims that crowd H01L 31.
Search this in Eureka →B82Y · Nanotechnology Applications
B82Y carries 9 patent records, nearly all attributable to IBM’s portfolio. Nanotechnology approaches — such as nanocrystalline silicon interlayers, nano-structured TCO morphologies, or quantum-dot assisted passivation — could offer performance gains over conventional a-Si:H stacks, yet the field is largely unexplored by solar-focused assignees. IBM’s presence suggests cross-sector technology transfer is plausible, but solar-specific nanotechnology claims remain sparse and represent an under-served adjacent branch for a materials-science-oriented entrant.
Search this in Eureka →How leading filers differ by IPC technology route
Route coverage across the main technology branches in the current evidence set.
| Player | H01L 31 · Semiconductor devices | H01L 51 · Semiconductor devices | H01L 27 · Semiconductor devices | B82Y 20 · Nanotechnology applications | H01L 21 · Semiconductor devices |
|---|---|---|---|---|---|
| French Alternative Energies and Atomic Energy Commission (CEA) | Strong · 27 | Moderate · 9 | Moderate · 9 | Absent | Absent |
| 3SUN SRL | Strong · 13 | Strong · 7 | Strong · 7 | Absent | Absent |
| IBM (International Business Machines Corporation) | Strong · 15 | Absent | Absent | Moderate · 7 | Emerging · 3 |
| State Power Investment Corporation Research Institute Co., Ltd. | Strong · 13 | Absent | Absent | Absent | Absent |
| Jiangsu Akcome Energy Research Institute Co., Ltd. | Strong · 12 | Absent | Absent | Absent | Absent |
| Jiangxi State Power Investment New Energy Technology Co., Ltd. | Strong · 11 | Absent | Absent | Absent | Absent |
| Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences | Strong · 10 | Absent | Absent | Absent | Absent |
Frequently asked questions
The corpus contains 177 patent families in scope. The applicant ranking and branch composition figures are derived from patent records, which can exceed the family total because a single family may be filed across multiple offices or classified under multiple IPC branches.
The Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA) of France holds the top position with 27 patent records, focused on H01L semiconductor device classes. Its closest ranked rival, Jiangxi State Power Investment New Energy Technology, holds 19 patent records.
The lifecycle stage is Decline: annual filings peaked at 31 records in 2021 and have eased since, with a recent-window growth rate of -16%. The field is commercially active and consolidated rather than collapsing, but the primary filing wave has passed. The most recent 18–24 months are under-counted due to publication lag.
China is by far the leading prosecution jurisdiction with 144 patent records, followed by the United States with 28, Europe (EPO) with 17, and WIPO (PCT) with 13. Japan and South Korea each carry only 2 records, which is low relative to their traditional strength in thin-film photovoltaics.
The most-cited work covers bifacial crystalline silicon / thin-film silicon heterojunction solar cells (43 citations), perovskite/silicon heterojunction tandem cell structures (40 citations), and silicon heterojunction solar cells and their manufacturing methods (35 citations). All top-cited patents focus on device architecture and fabrication rather than TCO materials alone.
The most lightly patented adjacent branches are C23C (coating and surface deposition, 6 records), B82Y (nanotechnology applications, 9 records), H10P (4 records), C25D (electroplating and electroforming, 3 records), and H10K (organic semiconductors, 3 records). C23C and B82Y carry the most plausible technical relevance to SHJ cell performance and represent areas where new process-focused or nanomaterials-focused claims could differentiate from the dense H01L 31 prior art.
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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.
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