Efficient electron injecting layer for PLEDs based on (PLAGH)_2[ZnCl_4]

摘要

Herein (PLAGH)_2[ZnCl_4] (PLAGH~+ = pyridoxalaminoguanidinium cation) is introduced as a new electron injecting layer for efficient polymer light emitting diodes based on the green-emitting copolymer poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(1,4-benzo-2,1',3-thiadiazole)] (F8BT). The device structure is glass/TTO/PEDOT:PSS/F8BT/ (PLAGH)_2[ZnCl_4]/Al, where (PLAGH)_2[ZnCl_4] was deposited from its water/methanol solution via spin-coating. In particular, it was found that the incorporation of (PLAGH)_2ZnCl_4] at the polymer/Al interface improved the luminous efficiency of die device (from 2.6 to 3.32 cd/A) and reduced the turn-on voltage, whereas an up to threefold increase in brightness (～ 14,106 cd/m~2 for (PLAGH)_2[ZnCl_4], as compared to ～5850 cd/m~2 for the reference device) was observed after annealing at 110 ℃.