SHJ a-Si/c-Si Interface Patent Snapshot 2026
The SHJ a-Si/c-Si interface patent space is a small, highly concentrated field of 10 patent families, dominated by EPFL with 6 families, alongside a single Chinese industrial filer and one Indian research institute. Activity peaked in 2017 and has since declined sharply, marking this as a post-peak, specialist niche with limited but potentially strategic white space in surface deposition and metal-compound processing routes.
EPFL commands the field with a dominant share among three active filers
The corpus contains 10 patent families across three applicants. EPFL leads with 6 patent families, followed by Tongwei Solar (Jintang) with 3 and the Institute of Physics Bhubaneswar with 1.
The top five filers account for 100% of the ranked applicants visible in this query’ combined total, reflecting extreme concentration — effectively a three-player field in which a single academic institution holds the majority position.
| # | Applicant | Patent families | Share |
|---|---|---|---|
| 1 | École Polytechnique Fédérale de Lausanne (EPFL) | 6 | |
| 2 | Tongwei Solar (Jintang) Co., Ltd. | 3 | |
| 3 | Institute of Physics Bhubaneswar | 1 |
EPFL’s dominance signals that foundational interface engineering IP in this niche originated largely in academic research, with Tongwei Solar representing the primary industrial challenger filing on device-level implementations.
The most recent one to two years are likely under-counted due to standard patent publication lag; the absence of filings in 2024–2026 should be interpreted cautiously rather than as confirmed silence. Longer-window growth, applicant concentration, and technology-route coverage are therefore more reliable signals than the latest-year bar alone.
A 2017 peak followed by persistent decline, with semiconductor device patents dominating the technology mix
The filing trend and IPC composition together reveal a field that burst briefly in 2017, receded, saw a modest revival in 2021, and has produced no recorded filings since. Semiconductor device classification (H01L) accounts for the entire corpus, with coating and metal-compound classes present at the margin.
Annual filing trend
Filings peaked at 5 families in 2017, dropped to zero in 2018, recovered modestly to 3 in 2021, and have since returned to zero through 2024–2026. Given standard publication lag, any activity filed in the last 18–24 months may not yet appear in the record.
↗ Hover for values · click a bar to ask EurekaTechnology composition
H01L (Semiconductor devices) covers all 10 families, confirming that interface IP is framed primarily in device-architecture terms. C01G (Compounds of other metals) and C23C (Coating and surface deposition) each appear in only 1 family, pointing to adjacent process-chemistry angles that are presently sparse.
↗ 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 | Silicon heterojunction solar cells and methods of … | 35 |
| 2 | Silicon heterojunction solar cells and methods of … | 11 |
| 3 | Silicon heterojunction solar cells and methods of … | 5 |
| 4 | High-efficiency silicon heterojunction solar cell … | 4 |
| 5 | High-efficiency silicon heterojunction solar cell … | 3 |
| 6 | Silicon heterojunction solar cells and methods of … | 2 |
| 7 | Silicon heterojunction solar cells and methods of … | 1 |
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.
Assignee snapshot from the current evidence set
The applicants below are visible in this query result. Because the evidence set is relatively small, read this section as a directional snapshot rather than a full competitive ranking.
EPFL
EPFL holds 6 patent families, all concentrated in H01L 31 (Semiconductor devices). The portfolio is Europe-anchored and academically originated, reflecting foundational interface-engineering research. No momentum data is available for the recent period, consistent with the post-peak filing environment.
families: 6Tongwei Solar (Jintang)
Tongwei Solar (Jintang) holds 3 patent families, also concentrated in H01L 31. As the sole industrial filer in this corpus, the company represents the only commercially scaled actor, though its portfolio remains narrow relative to EPFL’s foundational position. No recent momentum data is available.
families: 3Frequently asked questions
The corpus contains 10 patent families across three applicants. This is a small, specialist niche with activity concentrated in semiconductor-device classification.
EPFL (École Polytechnique Fédérale de Lausanne) is the leading filer with 6 patent families, all in the H01L 31 semiconductor-device class. Tongwei Solar (Jintang) holds 3 families as the primary industrial filer.
Annual filings peaked in 2017 with 5 families, dropped to zero in 2018, recovered briefly to 3 in 2021, and have recorded no filings since. The lifecycle is classified as Decline. The most recent 18–24 months may be under-counted due to publication lag.
Europe (EPO) leads with 4 patent records, followed by the United States with 3, India with 2, and a single WIPO PCT application. The EPO-first pattern reflects EPFL’s filing strategy.
No co-applicant or collaborative filings are recorded in this corpus. All three applicants appear to file independently, which is consistent with the academic origins of the visible portfolio.
Two adjacent IPC branches — C23C (Coating and surface deposition) and C01G (Compounds of other metals) — each contain only one patent record, representing 8% of IPC records each. These process-chemistry angles have plausible relevance to interface passivation and buffer-layer engineering but remain largely unclaimed at the patent level.
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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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