Device performances of exciplex organic light-emitting diodes with different emitting layer thickness

We demonstrated device performances of exciplex organic light emitting diodes (OLEDs) by using 4, 4', 4”-tris(N-3-methyphenyl-N-phenyl-amino) triphenylamine (m-MTDATA) and 4,7-diphenyl-1,10-phenanthroline (Bphen) as electron donor and acceptor materials, respectively with different emitting layer (EML) thicknesses. The maximum current efficiency and external quantum efficiency (EQE) of the optimized OLEDs are 11.3 cd/A and 4.02%, respectively. Transient electroluminescence (TrEL) was used to understand the carrier and exciton dynamics in the OLEDs. It was found that the thinner EML exhibited a shorter decay time in such devices.