posted on 2025-07-05, 16:04authored byYong Ha Hwang, Chan Young Kim, Kyung Cheol Choi
Fiber-based organic light-emitting diode (OLED) displays
have drawn
increasing attention due to their inherent wearability and the superior
performance characteristic of OLED technology. However, thin-film
transistor (TFT)-based circuit-level integration on cylindrical fiber
substrates has remained challenging due to their long and three-dimensional
geometry, which limits the implementation of multiterminal configurations
and x–y matrix structures.
Here, the fiber-based three-dimensional (3D) integrated OLED-TFT with
TFT-driven circuitry, enabled by a three-dimensional connective architecture
(3DCA), is reported. The 3DCA fully exploits the cylindrical surface
of the fiber by spatially separating active devices and signal terminals
onto the upper and lower surfaces, respectively. Lateral conduction
paths are formed through a simple tilting step during fabrication,
enabling vertical electrical interconnection without additional processing
and compensating for deposition shadowing on the sidewalls. As a result,
the fiber OLED display operates with circuit-driven control while
maintaining low gate leakage current (∼10–10 A). Furthermore, the 3DCA allows full encapsulation through 3D coverage
encapsulation strategies, ensuring stable operation even under water.
This architecture not only achieves high performance but also establishes
a TFT-based circuit beyond the device level, marking a paradigm shift
toward fully operational fiber displays.