Technical / research

NS Nanotech announced that its researchers from the University of Michigan, led by the company's co-founder Prof. Zetian Mi, has developed a native red sub-micron microLED device with an EQE of over 8%. The company says that this is the world's most efficient submicron-scale LED.

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NS Nanotech has an exclusive license to commercialize prof. Zetian's LED technology and technologies developed at McGill University. The company grows unique nanowire LEDs using MBE technology.

This is a sponsored post by XTPL

Say hello to the future of electronics with Ultra-Precise Deposition (UPD) technology! This cutting-edge method allows us to create intricate, high-resolution electronic devices with greater flexibility and precision than ever before. UPD is set to revolutionize the world of additive manufacturing, offering a much-needed solution for printing conductive and insulating structures on complex substrates.

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So, what is UPD, and why is it such a game-changer? It's a unique way of printing conductive and insulating materials onto various surfaces, both rigid and flexible. It helps fix defects in OLED displays and connects the tiny components in microLED arrays. The best part? It's versatile and adaptable to a wide range of applications, from flexible electronics to solar cells and MEMS devices.

Researchers from Korea's KIMM institute have fabricated full-color flexible microLED devices, using blue LEDs and perovskite quantum dot color conversion layers. The demonstrated device featured  1 mm pixel pitch LEDs (25.4 PPI) and could be bent with a radius of 5 mm without being damaged.

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The researcher used a perovskite-QD and siloxane composite using ligand exchanged PQD with silane composite followed by surface activation by an addition of halide-anion containing salt. Due to this surface activation, the researchers say that it was possible to construct the PQD surface with a silane ligand using a non-polar organic solvent that does not damage the PQD. As a result, the ligand-exchanged PQD with a silane compound exhibited high dispersibility in the siloxane matrix and excellent atmospheric stability.

Researchers from Korea's KAIST have found that by changing the epitaxial structure of microLEDs, it is possible to fundamentally resolve the problem of efficiency degradation in microLED devices. In other words, it is possible to create microLEDs in which the efficiency does not drop with size. 

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The researchers discovered that the specific epitaxial structure of the microLED changes how the current drives to the sidewall of the microLEDs. Based on that, the researchers developed a epitaxial structure that is not sensitive to sidewall defects. The proposed structure also reduces generated heat by about 40% compared to standard microLEDs.

China-based MicroLED microdisplay developer Jade Bird Display announced that it has developed a higher-efficiency AlGaInP-based (native) red microLED, that achieves a brightness of 750,000 nits, an increase of 50% compared to its currently-used emitter. The company says that this it the industry's brightest native red emitter.

JBD says that it managed to redistribute the local charge carriers by a breakthrough in surface treatment process and in this way, minimize the surface non-radiative recombination and boost the efficiency. The company says it expects to implement this technology in mass production by middle of 2023.

Researchers from the US and Korea, led by MIT, developed full-color vertically-stacked microLEDs that achieve the highest array density (5100 PPI) and the smallest size (4 µm) reported to date.

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To end up with such high resolution and small microLED chip size, the researchers used a 2D materials based layer transfer (2DLT) technique. The resulting microLEDs, that have near-submicron thickness, are grown on 2D material-coated substrates, removed, and then stacked.

Stacked-RGB microLED microdisplay developed Sundiode announced that it has achieved the successful growth of a monolithic, all-InGaN RGB LED structure on a single sapphire wafer. This structure was developed in collaboration with Soft-EPI.

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Sundiode's epitaxial technology enables stacked-RGB LEDs with multiple junctions, capable of emitting RGB colors independently. This structure makes it easier to produce ultra-high density microdisplays.

Toshiba Corporation announced that it has developed a new high-performance phosphor material that could be highly useful in microLED color conversion, among other applications. Toshiba aims to start mass producing the new material in 2025, and will soon offer samples for potential partners and customers.

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Toshiba says that the new material delivers excellent solubility in polymers or organic solvents, where it is transparent and colorless under visible light, and that emits persistent red-light emissions under UV light, with excellent color purity and a luminescence six times that of current phosphors.

Researchers from Korea-based KAIST institute developed a microLED-powered wearable patch that acts as an UV-induced inhibitor for melanogenesis, the creation of brown or dark pigments that can lead to skin diseases.

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LEDs have been used to photo-stimulate in skin care, but normal devices cannot conform to the skin shape, they operate from a distance which is problematic. If the patch is connected to the skin, it achieves much more effective photo-treatment. In this research, the team fabricated a 4x4 cm² wearable device made from an array of 100-micron sized microLED chips, vertically interconnected for high flexibility.