Apparatus and method for evaluating light stability of material for organic layer of organic light-emitting element

A method for evaluating photostability of a material for an organic material layer of an organic light emitting device, the method comprising:

• preparing an apparatus for evaluating photostability of the material for an organic material layer of an organic light emitting device, the apparatus comprising a photostability chamber provided with at least four light source zones:
• a first light source zone provided with a daylight light source with a color temperature of approximately 4,000K;
• a second light source zone provided with a white fluorescent light source with a color temperature of approximately 6,500K;
• a third light source zone provided with a UV-cut light source with a color temperature of approximately 3,000K and light only in a wavelength region between about 500 to 700 nm,
• a fourth light source zone to which no light is irradiated,
• placing a sample of the material in each of the at least four light source zones;
• irradiating daylight light with a color temperature of approximately 4,000K to the first light source zone, irradiating white fluorescent light with a color temperature of approximately 6,500K to the second light source zone, irradiating UV-cut light with a color temperature of approximately 3,000K and light having a wavelength region only between about 500 to 700 nm to the third light source zone, and maintaining the fourth light source zone without irradiating a separate light thereto;
• and
• evaluating photostability of the samples by retrieving each of the samples placed in the at least four light source zones and comparing each sample in the first, second, and third light source zones irradiated by the light to the sample of the fourth light source zone not irradiated with light, wherein a time of irradiating the daylight, the white fluorescent light and the UV-cut light is from 0.5 hours to 12 hours.