White organic light-emitting diodes prepared by a fused organic solid solution method

Abstract

This letter demonstrates a white organic light-emitting diode (OLED) with high color stability fabricated by using a single organic white-emitting layer. The dopants were introduced prior to the device fabrication process through organic solid solution process formed by high-temperature and high-pressure fusion process. A high band gap organic material, $\alpha$ -naphthlyphenylbiphenyl diamine, was adopted and precisely doped with several kinds of fluorescent dyes as the emitting material. The most important benefits of using this fused organic solid-solution technique are the precise control of dopants, ultrauniform mixture of dopants in the host, easy fabrication; and, as a result, the fabricated white OLEDs show extremely little color shift with increasing injection current. The simplified device fabrication process is believed to be beneficial to the white OLED display and lighting industrialization.