Organic light-emitting diode (OLED) electronic textiles capable of driving displays have been developed, raising expectations for their application in fashion and functional clothing.

KAIST announced on the 12th that a research team led by Professor Kyung-Cheol Choi of the Department of Electrical and Electronic Engineering developed an organic light-emitting diode (OLED) electronic fiber capable of outputting information.

Electronic textiles are attracting attention as a next-generation form factor because, unlike existing two-dimensional flat devices, they can adapt to various movements of the human body and provide excellent wearability and portability due to their one-dimensional structure.

In particular, light-emitting electronic textiles are attracting much attention due to their potential applications in various fields such as fashion, functional clothing, medical care, safety, and vehicle design.

On the other hand, previous research on luminescent electronic fibers has shown electro-optical performance that is insufficient for use as displays, or has been conducted only on a device-by-device basis or on a two-dimensional plane with a long aspect ratio, making it difficult to develop application technologies.

Professor Choi Kyung-chul's research team developed an OLED electronic textile display. To achieve this, the research team focused on building an addressing system while achieving high electro-optical performance. First, the research team designed an RGB phosphorescent OLED device structure suitable for a cylindrical fiber structure with a diameter of 300 micrometers (μm). Leveraging their proprietary dip-coating process, they developed an OLED electronic fiber with performance comparable to that of a planar OLED device.

In particular, phosphorescent OLEDs capable of achieving high efficiency were successfully implemented on fiber, demonstrating a luminance of up to 10,000 cd/m2 (candela/square meter) and a high current efficiency of 60 cd/A (candela/ampere). This figure represents a current efficiency approximately five times higher than that of existing technologies.

The research team also designed a contact area on the OLED electronic fiber to establish a woven addressing system for stable display operation based on the OLED electronic fiber. We also verified its wearable functionality by displaying information such as text.

Professor Choi's research team member stated that this electronic fiber has high current efficiency for low power consumption, low operating voltage, and addressability, which are essential for display devices.

“We focused on implementing the essential elements of technology required to implement fiber-based displays,” said Yong-Ha Hwang, a doctoral candidate in Professor Choi’s research team who led this study. “We expect that this will be suitable for various applications, such as fashion and functional clothing, by providing the excellent wearability and portability of electronic textiles while simultaneously implementing display functionality.”

The results of this study, led by Professor Kyung-Cheol Choi's research team and led by doctoral candidate Yong-Ha Hwang as the first author, were published online in the prestigious international academic journal in the field of nanotechnology, 'Advanced Functional Materials', on February 4, and were published as a front cover paper on May 3.

Meanwhile, this research was conducted with the support of the Ministry of Trade, Industry and Energy's Electronic Components Industry Core Technology Development Project and LG Display.