An organic solution to the Kelvin myth?

Many white light sources are described as having a “color temperature”, a practice that has been termed the “Kelvin myth”, since, in general, only incandescent light-emitters have a spectral distribution which closely approximates that of a black-body curve. We show that the white light emitted, via exciplex formation, from blends of two blue-emitting organic materials, has the same spectral form as black-body light, as perceived by the human eye. The color temperature is tunable, depending on the relative concentrations of the two materials. This suggests that organics could provide a white light source with a tunable, true, color temperature.