Researchers from Korea's Hanyang University, Yonsei University, and Sogang University have jointly developed new hole transport materials and processes that enable the fabrication of ultra high definition OLED microdisplays - achieving over 10,000 PPI.
The researchers explain that one of the problems with ultra-high-density OLED displays is that as the distance between pixels approaches the micrometer level, electrical signal interference which leads to light leakage from closeby pixels and a decrease in color fidelity. This leakage between subpixels occurs because the hole transport layer that facilitates the movement of holes is shared among the pixels that form the display.
The new hole transport materials and the ultra-fine patterning processes used by the researchers eliminated the cross talk and enabled the high resolution. 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.
