1. An organic light-emitting diode (OLED) device that produces white light, including:
a) an anode;
b) a hole-transporting layer disposed over the anode;
c) a blue light-emitting layer disposed over the hole-transporting layer, wherein the blue-light emitting layer comprises a host material and a blue-light emitting material, wherein the concentration of said blue-light emitting material is in a range of greater than 0 and less than 20% by volume of the host material wherein the blue light emitting material is selected from a bis(azinyl)amine boron complex;
d) an electron-transporting layer disposed over the blue light-emitting layer;
e) a cathode disposed over the electron-transporting layer;
f) wherein the hole-transporting layer comprises an entire layer or a partial portion of a layer in contact with the blue light-emitting layer and contains a light-emitting naphthacene compound having formula (I)
wherein
R1, R2, R3, R4, R5 and R6 represent substituents on each ring where each substituent is individually selected from alkyl or substituted alkyl groups of from 1 to 24 carbon atoms; aryl or substituted aryl groups of from 6 to 20 carbon atoms; carbon atoms from 4 to 24 necessary to complete a fused aromatic ring; heterocyclic or substituted heterocyclic groups of from 5 to 24 carbon atoms, which may be bonded via a single bond, or may complete a fused heteroaromatic ring system; alkoxy or aryloxy groups, ailcoxylamino, alkylaniino, and arylamino groups of from 1 to 24 carbon atoms; and fluorine, chlorine, bromine or cyano substituents;
a, b, c and d are individually selected from 0 through 5;
e and f are individually selected from 0 through 4;
provided that not all of a, b, c, d, e, and f are 0;
provided that at least one of R1 through R4 is not a fused ring group and at least one of R1 through R6 is a substituent; and
provided further that neither both R1 and R4 nor both R2 and R3 are heterocyclic; and
wherein the electron-transporting layer is transparent.
2. An organic light-emitting diode (OLED) device that produces white light, including:
a) an anode;
b) a hole-transporting layer disposed over the anode;
c) a blue light-emitting layer disposed over the hole-transporting layer, wherein the blue-light emitting layer comprises a host material and a blue-light emitting material, wherein the concentration of said blue-light emitting material is in a range of greater than 0 and less than 20% by volume of the host material wherein the blue light emitting material is selected from a perylene compound or its derivatives and a bis(azinyl)amine boron complex;
d) an electron-transporting layer disposed over the blue light-emitting layer;
e) a cathode disposed over the electron-transporting layer;
f) wherein the hole-transporting layer comprises an entire layer or a partial portion of a layer in contact with the blue light-emitting layer and contains a light-emitting naplithacene compound having formula (I)
wherein
R1, R2, R3, R4, R5 and R6 represent substituents on each ring where each substituent is individually selected from alkyl or substituted ailcyl groups of from 1 to 24 carbon atoms; aryl or substituted aryl groups of from 6 to 20 carbon atoms; carbon atoms from 4 to 24 necessary to complete a fused aromatic ring;
heterocyclic or substituted heterocyclic groups of from 5 to 24 carbon atoms, which may be bonded via a single bond, or may complete a fused heteroaromatic ring system; alkoxy or aryloxy groups, alkoxylamino, alkylamino, and arylamino groups of from 1 to 24 carbon atoms; and fluorine, chlorine, bromine or cyano substituents;
a, b, c and d we individually selected from 0 through 5;
e and f are individually selected from 0 through 4;
provided that not all of a, b, c, d, e and f are 0;
provided that at least one of R1 through R4 is not a fused ring group and at least one of R1 through R6 is a substituent; and
provided further that neither both R1 and R4 nor both R2 and R3 are heterocyclic;
wherein the hole-transporting layer and the blue-light emitting layers comprise hosts and emitting dopants and are co-doped with other dopants; and
wherein the co-dopant in the hole-transporting layer is t-BuDPN and the co-dopant in the blue-light emitting layer is NPB.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A color temperature tunable white light source comprising:
a first LED arrangement comprising at least one blue emitting LED configured to excite a remote phosphor and
a second LED arrangement comprising at least one red emitting LED,
wherein the LED arrangements are configured such that the composite light emitted by the LED arrangements appears white in color; and
wherein the relative drive currents of the LEDs is controllable, and variable in relative magnitude, such that the color temperature of the composite light emitted by the source is electrically tunable.
2. The light source of claim 1, wherein the relative drive currents of the blue and red LEDs are selected using a variable resistor configured as a potential divider.
3. The light source of claim 1, wherein the relative drive currents of the blue and red LEDs are selected using a pair of bipolar transistors.
4. The light source of claim 1, wherein the source is configured such that the relative magnitude of the drive currents is dynamically switched, and a duty cycle of the drive currents used to control the color temperature of the composite light emitted by the LED arrangements.
5. The light source of claim 4, wherein the source is configured with a pulse width modulated drive current to the blue and red LEDs and wherein the blue and red LEDs are driven on opposite phases of the pulse width modulated drive current.
6. The light source of claim 1, wherein the drive circuit providing the pulse width modulated current to the blue and red LEDs is a 555 timeroscillator circuit configured in an astable (free-run) mode of operation.
7. The light source of claim 1, wherein the remote phosphor associated of the first LED arrangement is selected from the group consisting of: a green light emitting phosphor, a yellow light emitting phosphor, and an orange light emitting phosphor.
8. The light source of claim 1, wherein the blue emitting LED emits blue light in a wavelength ranging from 440 nm to 470 nm.
9. The light source of claim 1, wherein the red emitting LED emits red light in a wavelength ranging from 620 nm to 640 nm.