EVALUATION METHOD AND EVALUATION DEVICE OF LIGHT-EMITTING ELEMENT

PROBLEM TO BE SOLVED: To nondestructively, precisely, and rapidly evaluate characteristic changes in a light-emitting element. SOLUTION: In an evaluation method of the light-emitting element such as an EL element equipped with at least a light-emitting layer between an electron injection electrode and a hole injection electrode, a light emission spectrum obtained by driving the light-emitting element is measured at a predetermined observation angle; and based on the differential spectrum between the reference spectrum at the same observation angle as the predetermined observation angle and the measured spectrum, presence/absence of a characteristic abnormality of the light-emitting element is determined. The observation angle can be improved in evaluation precision by having a plurality of the observation angles different in at least wavelength dependence characteristics of the differential spectrum from each other. An optical simulator is utilized which uses a light emission distribution parameter as the reference spectrum, and the parameter can be obtained by the fitting with the measurement spectrum. Based on such a process, the light emission distribution in the direction perpendicular to a light-emitting face in the light-emitting layer can be also determined. COPYRIGHT: (C)2009,JPO&INPIT