An ambipolar BODIPY derivative for a white exciplex OLED and cholesteric liquid crystal laser towards multi-functional devices

摘要

A new interface engineering method is demonstrated for the preparation of an efficient white organic light emitting diode (WOLED) by embedding an ultra-thin layer of the novel ambipolar red emissive compound 4,4-di-fluoro-2,6-di(4-hexylthiopen-2-yl)-1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indacene (bThBODIPY) in the exciplex formation region. The compound shows a hole and electron mobility of 3.3 × 10-4 cm2 V-1 s-1 and 2 × 10-4 cm2 V-1 s-1, respectively at electric fields higher than 5.3 × 105 V cm-1. The resulting WOLED exhibited a maximum luminance of 6579 cd m-2 with CIE 1931 color coordinates (0.39; 0.35). The bThBODIPY dye is also demonstrated to be an effective laser dye for a cholesteric liquid crystal (ChLC) laser. New construction of the ChLC laser, by which a flat capillary with an optically isotropic dye solution is sandwiched between two dye-free ChLC cells, provides photonic lasing at a wavelength well-matched with that of a dye-doped planar ChLC cell.