LIGHTING DEVICE COMPRISING AT LEAST TWO ORGANIC LUMINESCENT MATERIALS.

摘要

The invention provides a lighting device (100) comprising a light source (10) and luminescent materials (20). The luminescent materials (20) comprise a first organic luminescent material (120) and a second organic luminescent material (220), the light source (10) together with the luminescent materials (20) being configured to generate white lighting device light (101) during operation. The first organic luminescent material (120) degrades with time at a first degradation rate and the second organic luminescent material (220) degrades with time at a second degradation rate, wherein the first degadration rate is larger than the second degradation rate. The first organic luminescent material is configured in a first layer (130, 1020) and the second organic luminescent material is configured in a second layer (140, 1220). The first layer and/or the second layer is further configured to at least partly compensate for the difference in the first degradation rate and the second degradation rate in order to maintain the lighting device light (101) substantially white during operation time of the lighting device (100).