Low sublimation temperature cesium pivalate complex as an efficient electron injection material for organic light-emitting diode devices

摘要

Cesium pivalate ((CH_3)_3CCOOCs) has been synthesized and applied as an electron injection material for organic light-emitting diodes, which showed low sublimation temperature of 180 ℃. Typical bilayer structure of ITO/NPB (60 nm)/Alq_3 (50 nm)/EIL/Al was used to evaluate the electron injection efficacy of (CH_3)_3CCOOCs, the results showed (CH_3)_3CCOOCs/AI exhibits better electron injection than LiF/AI cathode and the power efficiency was improved by about 19% at current density of 50 mA/cm~2. More interestingly, in the typical three layer OLED structure ITO/2-TNATA (60nm)/NPB (10 nm)/Alq_3:2% C545T (40 nm)/ MADN (15 nm)/(CH_3)_3CCOOCs (2 nm)/AI, the maximum current efficiency is up to 20 cd/ A with Commission Internationale d'Eclairage (CIE_(x,y)) color coordinates of (x = 0.30, y = 0.65) at current density of 140 mA/cm~2, which indicates that the non-aromatic alkali metal complex can also have good match with the chemically stable compound and exhibit good electron injection properties.