EVALUATION METHOD OF CARRIER BLOCK PERFORMANCE IN ORGANIC ELECTROLUMINESCENT ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide an evaluation method capable of evaluating the carrier block performance, by using an organic EL element of real element structure.SOLUTION: In an evaluation method of the carrier block performance in an organic electroluminescent element using an impedance spectroscopy, a DC voltage equal to or higher than an emission threshold voltage is applied to the organic electroluminescent element and then an AC voltage is applied while superposing thereon. Frequency of the AC voltage is changed, and the frequency when the capacitance becomes 0 is measured.