The utilization of low‐temperature evaporable CsN₃‐doped NBphen as an alternative and efficient electron‐injection layer in OLED

Cesium azide (CsN₃) doped 2,9‐bis(naphthalen‐2‐yl)‐4,7‐diphenyl‐1,10‐phenanthroline (NBphen) has been demonstrated as an efficient electron‐injection layer (EIL) in this work. Advantageous for its low evaporation temperature and air stability, CsN₃ is employed as an n‐dopant to replace the reactive alkali metals or alkali metal compounds. Organic light‐emitting diodes utilizing this composite EIL exhibit highly improved current density–luminance–voltage characteristics compared to the control device with LiF. When C545T‐doped Alq₃ is used as an emitting layer, a maximum current efficiency of 10.4 cd A⁻¹ can be reached. Our results indicate that this CsN₃‐doped NBphen composite layer has great potential as an alternative EIL in organic electronic devices.