Effect of YF_3 Electron Injection Layer on The Performance of Organic Light-emitting Devices

Organic light emitting devices( OLEDs) were fabricated with yttrium fluoride( YF3) as the electron injection layer instead of lithium fluoride( Li F) and aluminum as the cathode. The experiment results show that YF3 injection buffer layer with appropriate thickness can effectively enhance the electron injection ability of the cathode,leading to more balanced concentration of electrons and holes,and optimized electroluminescent properties of OLEDs. The device with 1. 2 nmthick YF3 layer has the minimum turn-on voltage of 2. 6 V,the maximum current efficiency of 8. 52cd·A- 1,and the maximum luminance of 36 530 cd·m- 2. Compared with Li F reference sample,the maximum brightness and current efficiency are increased by 39% and 53%,respectively.