COSDAF Home OLED HomeResearch HighlightResearch ProjectInnovative and Technology Funding

 

Advanced Materials, Devices and Processing Technologies for Organic Light-Emitting Devices (OLED)

 

Funding Supported by:

 

Significant Achievements (April 2006 - March 2007):

 

White-Emitting OLED

1. Fabrication of white OLED using yellow and sky blue emitting materials with current efficiency and power efficiency of 11 cd/A and 6 lm/W, respectively. The CIE coordinates are (0.30, 0.38) and the lifetime is projected to be over 10,000 hours at an initial brightness of 100 cd/m2.

2. Fabrication of white OLEDs using a new blue phosphorescent dye Iridium (III) tris(5-(2,4-difluoro-phenyl)-10,10-dimethyl-4-aza -tricycloundeca-2,4,6-triene) (Ir(F2-mppy)3) co-doped into the DCM and CBP host with a current efficiency close to 10 cd/A.

3. Fabrication of white OLED using orange and sky blue emitting materials with a power efficiency of 5.6 lm/W. The CIE coordinates fall within (0.3-0.4, 0.3-0.4) at all operating voltages.

4. Fabrication of white OLED using our newly synthesized white-emitting material, TPyPA, with a power efficiency > 8 lm/W for current density operating at <30mA/cm2. The device gave a pure white color with CIE coordinates (0.31-0.32, 0.35-0.36).

5. Fabrication of white OLED using our newly synthesized florescent host, 2, 7-dipyrenyl-9, 9’-dimethyl-fluorene (DPF), with a current efficiency > 10 cd/A and luminance >10,000 cd/m2 at 9V.

6. Succeeded in adopting yellow and light blue emitting materials to develop a very bright white OLED with a power efficiency of 8.7 lm/W, which broke the world-record to achieve the highest power efficiency of white OLED by using florescent materials. Its efficiency enhancement and voltage reduction were achieved by doping BPhen into the light-emissive layer. With an optimal doping concentration, the device with BPhen dopant exhibits a power efficiency 74% higher than the reference device (5.0 lm/W). The results have been submitted to Applied Physics Letters for publication. NEW!

 

 

    

 

Super Bright White OLED with Power Efficiency > 8 lm/W

 

Flexible OLED and Thin Film Encapsulation

1. Fabrication of ITO on PC, PET and PEN at a temperature lower than 90 degree Celsius with optical transparency >85%, RMS surface roughness <2 nm, peak roughness <40 nm, and electrical conductivity <16 ohm/sq.

2. Fabrication of high-efficiency red, green and blue-emitting flexible OLED with current efficiency of 4.3, 11.5 and 8.5 cd/A, respectively. At a driving voltage of 9V, the devices exhibit luminance of >2,000 (red), >10,000 (green), and >5,000 cd/m2 (blue). NEW!

 

Super Bright Red, Green and Blue-Emitting Flexible OLED

 

New Materials

1. Synthesis of a new blue phosphorescent dye Iridium (III) tris(5-(2,4-difluoro-phenyl)-10,10-dimethyl-4-aza -tricycloundeca-2,4,6-triene) (Ir(F2-mppy)3).

2. Synthesis of three blue florescence dyes: 2-tert-butyl-9, 10-di (2-naphthyl) anthracene (TBADN), 2- tert-butyl-9, 10-di (9-phenanthryl) anthracene (TBDHA), and 2- tert-butyl-9, 10-di (1-pyryl) anthracene (TBDPA).

3. Synthesis of a blue-emitting material, 2,7-di(1-pyrenyl)-9,9’-di(3-(9-phenyl-carbazoyl))-fluorene (DCDPF), for florescent OLED, with CIE coordinates (0.15, 0.15). The device exhibited current and power efficiency of 4.5cd/A and 3.2 lm/W. The luminance is >8,000 cd/m2 for a driving voltage at 9V.

4. Succeeded to apply an organic-inorganic hybrid (WO3+Mg:Alq3) as a connection unit for stacked OLED. This connection unit led to a stacked OLED with a luminous efficiency twice that of a single-unit OLED.

5. Usage of C60 and Yb:BPhen, a kind of organic-nanomaterial hybrid, to adjust the barrier height for charge injection in OLED. Electron injection barrier significantly reduces upon Yb doping.

6. Usage of 2,7-dipyrene-9,9'-dimethyl fluorene (DPF) as a singlet host for florescent red-emitting OLED. The current and power efficiency are 50% higher than that using a conventional host, Alq3. The luminance is 6,500 cd/m2 for a driving voltage of 9V. NEW!

7. Synthesis of a triplet host, 1,6-bis(4-N-carbazole-phenyl) cyclohexane (CPBCH), for phosphorescence blue-emitting OLED. At 20mA/cm2, the current and power efficiency is 11.5 cd/A and 6 lm/W, respectively, which are 30% higher than that using a conventional host, CBP. The luminance is >3,800 cd/m2 for a driving voltage of 9V. NEW!