Abstract
Relation of hole transport material and running durability was studied. Triphenylamine derivatives were used as hole transport materials, and examined the stability of amorphous state and running durability. The lifetime (to 1/2 initial luminance) of EL device using Alq and TPA oligomer, which is the highest thermostable hole transport material among the examined ones, is found to be 2000 hours for initial level of 500 cd/m^2.
