Efficient top-emitting organic light-emitting diodes with a V_2O_5 modified silver anode

摘要

We fabricated efficient top-emitting organic light-emitting diodes (OLEDs) with silver (Ag) as an anode and samarium (Sm) as a semi-transparent cathode. The hole-injection barrier at the Ag anode/hole transporter interface is reduced by inserting a buffer layer of vanadium oxide (V_2O_5) between them. The ultraviolet photoelectron spectroscopy analysis shows that the hole-injection barrier is reduced by 0.5 eV. Both the V_2O_5 thickness and the organic layer thickness are optimized. The optimized device achieves a maximum current efficiency of 5.46 cd A~(-1) and a power efficiency of 3.90 lm W~(-1), respectively.