High-color-temperature tandem white OLED
View Patent ↗An OLED device having two spaced electrodes including: first, second, and third light-emitting units disposed between the electrodes, the first light-emitting unit produces light that has multiple peaks at wavelengths longer than 500 nm and substantially no emission at wavelengths shorter than 480 nm, and the second and third light-emitting units produce light that has substantial emission at wavelengths shorter than 500 nm; intermediate connectors respectively disposed between the first and second light-emitting units, and between the second and third light-emitting units; and wherein the OLED device emits light with a color temperature greater than 7,000K.
1. An OLED device having two spaced electrodes comprising:
a. first, second, and third light-emitting units disposed between the electrodes, the first light-emitting unit produces light that has multiple peaks at wavelengths longer than 500 nm and substantially no emission at wavelengths shorter than 480 nm, and the second and third light-emitting units produce light that has substantial emission at wavelengths shorter than 500 nm;
b. intermediate connectors respectively disposed between the first and second light-emitting units, and between the second and third light-emitting units; and
c. wherein the OLED device emits light with a color temperature greater than 7,000K.
2. The OLED device of claim 1 wherein the device emits light with a color temperature between 9,000K and 13,000K.
3. The OLED device of claim 1 wherein the second and third light-emitting units each include a light-emitting layer comprising a host material and a blue-light-emitting dopant.
4. The OLED device of claim 3 wherein the blue light-emitting dopant is a singlet light-emitting compound.
5. The OLED device of claim 3 wherein the blue light-emitting dopant is a triplet light-emitting compound.
6. The OLED device of claim 1 wherein the first light-emitting unit includes a singlet light-emitting compound.
7. The OLED device of claim 1 wherein the first light-emitting unit includes a triplet light-emitting compound.
8. The OLED device of claim 1 wherein the second and third light-emitting units have the same emission spectra.
9. The OLED device of claim 1 wherein the second and third light-emitting units have different emission spectra.
10. The OLED device of claim 1 wherein one of the spaced electrodes is reflective and the other is transmissive and the first light-emitting unit is disposed closer to the reflective electrode than the second and third light-emitting units.
11. The OLED device of claim 1 further including an array of at least three different color filters associated with the device that receives light from the light-emitting units, the bandpass of each of the color filters being selected to produce different colored light.
12. The OLED device of claim 11 wherein the array of at least three different color filters forms an RGBW device.