磷光敏化白光電化學元件

Abstract

本篇論文提供了一種利用磷光敏化發光原理，達到White Light-Emitting Electrochemical Cells (WLECs) 系統，將利用發藍綠光的離子錯合物[Ir(dfppz)2(dtb-bpy)]+(PF6─) (其中的dfppz為1-(2,4-difluorophenyl)pyrazole而dtb-bpy為 [4,4′-di(tert-butyl)-2,2′-bipyridine])當作主體，再以高效率紅色螢光染料 Sulforhodamine 101當作客體，利用磷光敏化發光原理改善元件的效率。 在主客體的光激發頻譜中顯示趨近於白光的光激發頻譜，而在低摻雜濃度0.3 wt%的客體中，進而提高發光效率達到7.9 %及能源效率達到15.6 lm/w，以0.5 wt%摻雜濃度的客體中，CIE色坐標可達到(0.33 0.33)，CRI演色性指數可達到79，這是目前固態白光電化學元件效率的最高記錄，實現了磷光敏化發光的方法能有效提昇白光電化學元件的效率。

We report phosphorescent sensitized white light-emitting electrochemical cells (WLECs). The emission layer is host-guest system containing an efficient blue-green emitting phosphorescent ionic transition metal complex, [Ir(dfppz)2(dtb-bpy)]+(PF6─) as the host and an efficient red-emitting fluorescent dye, Sulforhodamine 101 as the guest. Phosphorescent sensitization was used to improve efficient of device. The device doped with 0.3 wt% guest concentration achieve peak EQE and power efficiency up to 7.9 % and 15.6 lm/W, respectively. Moreover, the device with 0.5 wt% guest concentration achieve CIE of (0.33, 0.33) and CRI up to 79. The device efficiencies achieved are among the highest reported for WLECs and thus confirm that phosphorescent sensitization is useful for achieving highly efficient WLECs.