Wavelength-Tunable Textile-Based Organic Light-Emitting Diode for Multifunctional Wearable Photomedical Applications and Display with Cool White to Warm White Light

A textile-based organic light-emitting diode (OLED) for wearable devices can be used actively in various fields such as phototherapy and display. It could significantly impact integrated development. However, there have been no reports of color-tunable OLEDs based on textiles for therapeutic applications at multiwavelengths. This paper proposes a parallel-stacked OLED with wavelength-tunable properties through AC driving, utilizing advantages of wearable textiles. Through this, red and greenish blue were output from the stacked OLED to realize white light based on the textile platform, and the color adjustment from cool white to warm white was successfully achieved by controlling the wavelength. In addition, the parallel-stacked OLED exhibits the same tendency as a single OLED device, and it can be operated stably even at low voltage. Therefore, it demonstrates that it can be utilized for phototherapy through forward and reverse operation and optoelectronics engineering applications. It can also be applied as a display by outputting white light.