In this dataset, it means a filing that combines QLED or QD-LED device terminology with a specific efficiency claim element: external quantum efficiency, electroluminescence efficiency, charge balance optimisation, or efficiency droop mitigation, classified under IPC codes covering organic-semiconductor devices, light-emitting materials, or nanotechnology applications. That excludes general quantum dot synthesis patents that do not tie back to a device efficiency claim, and excludes general OLED patents that do not involve quantum dots at all. The 49 families in this landscape were selected on that combined basis.

Filing here is led by a mix of Chinese corporate and university assignees alongside North American materials suppliers, with the most active applicants shown in the ranking table on this page rather than a fixed top-five list, since ranking order shifts as new records are indexed. No single assignee shows filing activity in the most recent tracked year, which suggests the field's leadership is more a matter of accumulated position from 2018–2020 filings than of current output. Co-filing is uncommon, with only three co-assignee pairings across the full 49-family set.

The dataset shows a peak of 12 families in 2019, dropping to 4 by the 2022 midpoint and showing no later filings in the tracked window. This pattern is consistent with an early land-grab on core device architecture and charge-balance claims, after which later entrants either found less open claim space or shifted filing into adjacent, more specific technology areas not fully captured by this search string. It is worth noting that publication lag of roughly 18 months means very recent filings, especially 2025 and 2026, will be undercounted here regardless of actual applicant activity.

The thinner IPC classes in this dataset, including B82Y nanotechnology applications, H01B conductors and insulators, C09D coatings, H10H light-emitting devices and C01G metal compounds, carry far fewer records than the dominant H10K and C09K classes. Specific sub-areas worth checking include thermoelectrically-assisted up-conversion mechanisms, non-Cd II-VI quantum dot formulations, and dielectric/metal/dielectric electrode stacking, all of which appear in the dataset but at low density relative to core layer-architecture claims. A thin count can mean either genuine open space or a search-term gap, so it is worth confirming with a broader claim-text search before filing.

The United States and China dominate receiving-office activity in this dataset at 16 and 15 filings respectively, with Europe, WIPO/PCT, Canada and the United Kingdom trailing well behind in single digits. That concentration suggests most competitive activity and litigation risk sits in those two jurisdictions, while the rest of the world, including the EU, remains comparatively lightly filed. Applicants planning international protection should weigh whether the six WIPO/PCT filings recorded here indicate broader international strategies still in national-phase entry.