High-efficiency fluorescent organic light-emitting diodes with MoO3 and PEDOT : PSS composition film as a hole injection layer

It has been demonstrated that high efficiency and low efficiency roll-off can be achieved in C545T-based green organic light-emitting diodes (OLEDs) by using molybdenum oxide (MoO3)/poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT : PSS) as the interfacial modification layer on indium tin oxide (ITO). The maximum current efficiency (CE), power efficiency (PE), and external quantum efficiency (EQE) reaches 23.4 cd A−1, 19.5 lm W−1, and 6.3% at 1000 cd m, respectively, and slightly reduces to 22.3 cd A−1, 8.3 lm/W and 6.0% at 10 000 cd m−2 In addition, the dependence of device performance on the thickness of the hole transport layer (HTL) on the top of MoO3 and PEDOT : PSS was also investigated. The results indicate that MoO3 as a HIL requires a thicker HTL in order to obtain high efficiency compared with PEDOT : PSS as HIL.