Individually addressable nanoscale OLEDs

When reducing pixel size below the wavelength of light, the conventional stacked geometry of organic light-emitting diodes (OLEDs) is dominated by sharp nanoelectrode contours. This causes spatially imbalanced charge carrier transport and recombination resulting in low external quantum efficiency (EQE) and filament formation accelerating device failure. Here, we circumvent these limitations by selectively passivating nanoelectrode edges with an insulating layer, while simultaneously defining a nanoaperture in flat areas. We thereby ensure controlled charge carrier recombination and suppress filament growth. After demonstrating efficient hole injection by gold nanoelectrodes, we realize individually addressable subwavelength OLED pixels (300 nanometers by 300 nanometers) based on plasmonic gold patch antennas for light extraction. We achieve an EQE of 1%, a maximum luminance of 3000 candela per square meter, and fast response times exceeding video rates. Our results highlight a scalable strategy to overcome key electronic and optical bottlenecks of nanoscale optoelectronic devices and demonstrate the potential of plasmonic patch antennas for high-density, high-performance OLED integration.