White light tandem OLED

• US 7,816,859 B2
• Filed: 04/30/2007
• Issued: 10/19/2010
• Est. Priority Date: 04/30/2007
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Inventors: Spindler, Jeffrey P., Hatwar, Tukaram K.
• Primary Examiner(s): Patel; Nimeshkumar D.
• Assistant Examiner(s): Bowman; Mary Ellen
• Application Number:
  US11/741,911
• Publication Number:
  US 20080268282A1
• Time in Patent Office: 1,268 Days
• Field of Search: 313504-506, 428/690
• US Class Current: 313/504
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• CPC Class Codes: C09K 2211/1011 Condensed systems
• CPC Class Codes: C09K 2211/1014 bridged by heteroatoms, e.g. N, P, Si or B
• CPC Class Codes: C09K 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: C09K 2211/1033 with oxygen
• CPC Class Codes: C09K 2211/1037 with sulfur
• CPC Class Codes: C09K 2211/1044 containing two nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/1088 containing oxygen as the only heteroatom
• CPC Class Codes: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 85/322 comprising boron
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/60 Organic compounds having low molecular weight H10K85/10 - H10K85/50 take precedence
• CPC Class Codes: H10K 85/624 containing six or more rings
• CPC Class Codes: H10K 85/626 containing more than one polycyclic condensed aromatic rings, e.g. bis-anthracene
• CPC Class Codes: H10K 85/633 comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen atom
• CPC Class Codes: H10K 85/654 comprising only nitrogen as heteroatom H10K85/652 takes precedence
• CPC Class Codes: H10K 85/657 : Polycyclic condensed heteroaromatic hydrocarbons
• CPC Class Codes: Y02B 20/00 : Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A tandem white light-emitting OLED device is disclosed comprising a spaced anode and cathode, a light reflector associated with either the anode or the cathode, and at least two white light emitting units. The first white light-emitting unit has a set of at least two emission peaks in the blue and yellow spectral regions that are more intense than any other emission peaks that may be present in the emission spectrum of the first white light-emitting unit. The second white light-emitting unit is disposed closer to the reflector than the first white light-emitting unit and includes a set of at least three emission peaks in the blue, green, and red spectral regions that are more intense than any other emission peaks that may be present in the emission spectrum of the second white light-emitting unit. An intermediate connector is disposed between the first and second white light-emitting units.

Claims

1. A tandem white light-emitting OLED device comprising:

a. a spaced anode and cathode wherein the cathode is reflective metal including aluminum or an alloy of aluminum and the anode is a light transmissive conductive metal oxide;

b. a first white light emitting unit having an emission spectrum that includes a first set of at least two emission peaks that are more intense than any other emission peaks that may be present in the emission spectrum of the first white light-emitting unit, such first set including;

i. a first blue spectral component having a first blue peak emission wavelength of between 440 and 490 nm; and

ii. a yellow spectral component having a yellow peak emission wavelength of between 550 and 590 nm;

c. a second white light-emitting unit disposed closer to the reflective metal cathode than the first white light-emitting unit, such second white light-emitting unit having an emission spectrum that includes a second set of at least three emission peaks that are more intense than any other emission peaks that may be present in the emission spectrum of the second white light-emitting unit, such second set including;

i. a second blue spectral component having a second blue peak emission wavelength of between 440 and 490 nm;

ii. a green spectral component having a peak emission wavelength of between 500 and 540 nm; and

iii. a red spectral component having a peak emission wavelength of between 600 and 700 nm; and

d. an intermediate connector disposed between the first and second white light-emitting units.

2. The tandem white light-emitting OLED device of claim 1 wherein the intensity of the yellow peak emission is at least 50% of the intensity of the second blue peak emission.

3. An OLED display device comprising:

a. an array of individually addressable pixels, each pixel including;

i. a spaced anode and cathode wherein the cathode is reflective metal including aluminum or an alloy of aluminum and the anode is a light transmissive conductive metal oxide;

ii. a first white light emitting unit having an emission spectrum that includes a first set of at least two emission peaks that are more intense than any other emission peaks that may be present in the emission spectrum of the first white light-emitting unit, such first set including a first blue spectral component having a first blue peak emission wavelength of between 440 and 490 nm a yellow spectral component having a yellow peak emission wavelength of between 550 and 590 nm;

iii. a second white light-emitting unit disposed closer to the reflective metal cathode than the first white light-emitting unit, such second white light-emitting unit having an emission spectrum that includes a second set of at least three emission peaks that are more intense than any other emission peaks that may be present in the emission spectrum of the second white light-emitting unit, such second set including a second blue spectral component having a second blue peak emission wavelength of between 440 and 490 nm a green spectral component having a peak emission wavelength of between 500 and 540 nm, and a red spectral component having a peak emission wavelength of between 600 and 700 nm; and

iv. an intermediate connector disposed between the first and second white light-emitting units; and

b. an array of at least red, green, and blue color filters associated with the array of pixels that receives light from the white light-emitting units, the band pass of each of the color filters being selected to produce red, green, or blue colored light.

4. The OLED display device of claim 3 wherein the frill width at half maximum for each of the blue, green, and red spectral components is within the band pass of the corresponding blue, green, and red color filter.

5. The OLED display device of claim 3 wherein the intensity of the first yellow peak emission is at least 50% of the intensity of the first blue peak emission.