Effect of LiF buffer layer on the performance of organic electroluminescent devices

Inserting LiF buffer layer between NPB and Alq3 can also enhance the efficiency of the device. A 0.3 nm LiF layer shows the optimal effects in this work, explained based on tunneling theory. The device with two LiF buffer layers both at the organic–organic interface and at the cathode–organic interface respectively showed the highest luminance of 23000 cd/m2 at a fixed bias of 20 V.