Researchers create 90-nanometer LEDs for future ultra high-resolution displays

90-nanometer LEDs enable ultra high-res displays with 127,000 PPI density.

: Researchers at Zhejiang University and University of Cambridge have developed nano-PeLEDs with pixel lengths of 90 nanometers, leading to an unprecedented pixel density of 127,000 pixels per inch. The new LEDs, based on perovskite semiconductors, surpass the limitations of traditional micro-LEDs and maintain 20% efficiency even at a miniaturization of 180 nanometers. To address the fabrication challenge of fragile perovskite material, researchers employed a unique lithographic insulation layer technique. Collaborating with LinkZill, the team created an active-matrix display prototype driven by thin-film transistor technology.

The technological frontier of display technology has reached a new milestone with researchers from Zhejiang University and the University of Cambridge unveiling the world's tiniest light-emitting diodes (LEDs), known as nano-PeLEDs. The defining feature of these LEDs is their microscopic size, with pixel dimensions as minute as 90 nanometers, which allows for an unparalleled pixel density of 127,000 pixels per inch (PPI). For context, a consumer gaming monitor measuring 27 inches and offering a 4K resolution typically manages a pixel density of just 163 PPI, highlighting the significant leap in capability enabled by these nano-PeLEDs.

The nano-PeLEDs are synthesized from halide perovskites, semiconductors more commonly associated with solar technology. Unlike conventional micro-LEDs, which see rapid declines in efficiency when pixel dimensions shrink past 10 micrometers, nano-PeLEDs maintain performance even on a nanoscale, with efficiencies hovering around 20% for pixels as small as 3.5 microns. A critical advantage of using perovskites lies in their minimal performance degradation relative to traditional III-V semiconductors, positioning nano-PeLEDs as a potential frontrunner for applications necessitating ultra-small pixel arrangements.

A significant obstacle addressed in this development involved the manipulation of the perovskite material, which is naturally fragile and sensitive to conventional fabrication methods like photolithography. The research team circumvented this issue by crafting a localized contact fabrication approach. By embedding lithographically patterned windows into an insulating layer, the delicate perovskite material could be secured, thus facilitating the maintenance of high-resolution image outputs while protecting the integrity of the semiconducting layers beneath.

The collaboration between Zhejiang University researchers and LinkZill, a company rooted in thin-film transistor (TFT) technology, has been instrumental in advancing potential applications of nano-PeLED technology. The joint endeavor led to the successful creation of a prototype active-matrix micro-PeLED display. This prototype is driven by a TFT backplane, a milestone step toward the commercialization of nano-PeLED technologies. Such integration is vital for applications requiring dynamic content display, as it underscores the technology's practicality and economic feasibility for widespread industry adoption.

Future implications for nano-PeLED technology are broad and exciting. With potential utility across diverse sectors ranging from medical imaging to gaming and augmented reality, the ultra-high resolution achieved by nano-PeLEDs could redefine display standards. As continued refinement and research emerge, these applications are expected to deepen, potentially shaping the future of high-resolution display technologies.

Sources: TechSpot, Nature

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