Domestic researchers have developed core technology for ultra-high-definition organic light-emitting diode (OLED) microdisplays. By minimizing electrical signal interference between pixels, this technology allows for clear image quality even in high-density pixel environments, which is expected to maximize immersion in virtual reality (VR) and augmented reality (AR) content.
The National Research Foundation of Korea announced on the 12th that a joint research team consisting of Professor Kim Do-hwan from Hanyang University, Professor Jo Jung-ho from Yonsei University, and Professor Kang Moon-sung from Sogang University has developed core technology for ultra-high-definition OLED microdisplays that can achieve clear image quality without signal interference even in high-density pixel environments. A microdisplay is a display with a size of less than 1 inch.
As the demand for realistic content utilizing extended reality technologies such as virtual reality (VR), augmented reality (AR), and mixed reality (MR) increases, the development of OLED microdisplays that can provide lifelike visual information and immediate immersion has become increasingly important.
However, as display resolution increases and the distance between pixels approaches the micrometer (㎛) level, electrical signal interference has occurred, leading to a decrease in color gamut and color purity. When voltage is applied to the OLED, electrons and holes emerge from the cathode and anode, respectively, and meet to emit light. This leakage current occurs because the 'hole transport layer' that facilitates the movement of holes is shared among the pixels that form the display.
The research team succeeded in implementing high-resolution OLED devices without signal interference by developing organic semiconductor hole transport materials capable of ultra-fine patterns with over 10,000 pixels per inch (ppi). By creating the hole transport layer with fine patterns, they can block the leakage current flowing to nearby pixels and minimize electrical signal interference. The team also optimized the silicon concentration of the hole transport layer to control the hole transport speed and enhance the light emission efficiency of the OLED.
Professor Kim Do-hwan noted, "The significance of this research achievement lies in dramatically improving the phenomenon of pixel interference that could not be resolved with existing microdisplay materials and patterning processes," and added, "It is expected to expand the application possibilities of high-resolution microdisplays for constructing ultra-realistic extended reality and contribute to acceleration as well."
The research results were published online in the international journal "Nature Electronics" on the 27th of last month.
References
Nature Electronics (2025), DOI: https://doi.org/10.1038/s41928-024-01327-5