One assignee leads the ranked list with 187 records, well ahead of the fifth-placed assignee at 42. The top five assignees combined hold 580 of the 1,084 records in scope, or 53.5%, so leadership is concentrated in a small group even though 100 companies appear somewhere in the ranking. Many of the largest holders are universities and display-industry firms whose IP predates dedicated perovskite research, since much of the underlying chemistry originates in OLED and organic semiconductor work.

Filings peaked so far at 55 in 2025, but the only reliable year-over-year comparison, 2021 to 2024, shows a 27% decline from 52 to 38 records. Publication lags filing by roughly 18 months, so the 2025 and 2026 counts are still incomplete and should not yet be read as a rebound or a continued slide. A clearer read on the recent trend will only be possible once another year or two of data has published.

The two dominant IPC subclasses are H10K, organic semiconductors including OLED-derived art, covering 76.8% of the 1,084 records, and H01L, semiconductor devices generally, covering 71.5%. Smaller but still meaningful shares sit in C09K materials, C07D heterocyclic compounds, H05B lighting circuits, H10D semiconductor devices and B05D coating processes. Because a single record can carry several class codes, these percentages add up to well over 100% and should not be summed together.

Coating-process claims under B05D sit at only 5.4% of records, and narrower functional areas such as substrate wetting control, sputter damage protection and dopant-free transport formulations show comparatively thin coverage against the dense core composition and device-architecture claims. These branches are good candidates for a freedom-to-operate check before committing to a full filing strategy, since the crowded ground is squarely in the H10K/H01L material and device claims rather than in these process-level details.

US12604596B2, assigned to Hanwha Solutions and published in April 2026, covers a manufacturing method that oxidizes a metal-oxide hole transport layer using an oxidative agent, UV/ozone, oxygen plasma or nitrogen dioxide gas, then sequentially laminates a perovskite layer and an electron transport layer on top. It is a process claim tied to a specific oxidation step and layer sequence rather than a composition claim, so it constrains how a metal-oxide HTL is prepared and sequenced rather than blocking transport-layer materials generally. Anyone using a different oxidation approach or layer order would sit outside its literal scope, though a full freedom-to-operate review would need to check dependent claims in detail.