Evidence map›Paper›PMID 41714347›Full record

ArticleScientific reports2026

Ultra-directional and high-efficiency µLEDs via gradient index filled micro-horn collimators.

Alexander Luce, Rasoul Alaee, Aimi Abass

Abstract read
In one paragraph

Article in Scientific reports, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Alexander LuceFriedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany. alexander.luce@fau.de.ORCID http://orcid.org/0000-0002-9659-6579
Rasoul Alaeeams-OSRAM, Regensburg, Germany.ORCID http://orcid.org/0000-0003-2187-4949
Aimi Abassams-OSRAM, Regensburg, Germany.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Micro-LEDs (µLEDs) are poised to transform near-eye AR/VR, display, and optical communication technologies, but they are currently hindered by low light extraction efficiency and non-directional emission. Our study introduces an innovative approach using a descending index multilayer anti-reflection coating combined with a horn collimator structure atop the µLED pixel. This design leverages the propagation of light outside the critical angle to enhance both the directionality and extraction efficiency of emitted light. By implementing either discrete or continuous refractive index gradients within the horn, we achieve a tenfold increase in light extraction within a [Formula: see text] cone, with an overall light extraction efficiency reaching approximately 80%, where 31% of the power is concentrated within this narrow cone. The enhancement is furthermore maintained across a broad range of Quantum well position variations. This performance surpasses that of an optimized SiO2 half-ellipsoidal lens, which diameter and height is 24X and 26X larger than the pixel width respectively, while our design only slightly increases the device height and expands the final light escape surface to 3 times and roughly 4 times the pixel width respectively. Such efficiency, directionality enhancement, and compactness make this solution particularly suitable for high-resolution, densely packed µLED arrays, promising advancements in high-performance, miniaturized display systems.

Indexed as

DirectionalityFDTDLight extraction efficiencynanoLEDNear-eye AR/VROutcoupling structureµDisplayµLED

Identifiers

PMID41714347
PMCPMC12923810

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.