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.