Exceptionally high brightness and long lifetime of efficient blue OLEDs for programmable active-matrix display

Area of Science:

• Materials Science
• Organic Electronics
• Photochemistry

Background:

• Blue phosphorescent OLEDs (Ph-OLEDs) struggle with efficiency, stability, and brightness, hindering advanced display applications.
• Existing blue Ph-OLED technologies require significant improvements to meet performance demands.

Purpose of the Study:

• To develop novel iridium(III) emitters for enhanced blue Ph-OLED performance.
• To improve the efficiency, stability, and brightness of blue Ph-OLEDs through molecular design.

Main Methods:

• Synthesized two novel Ir(III) emitters with 3,6-di(tert-butyl)-9H-carbazolyl (tBuCz) substituted tridentate carbene pincer ligands.
• Designed complexes (tBuCz-m-CF3 and tBuCz-p-CF3) to increase steric hindrance and reduce exciton accumulation.
• Fabricated and characterized Ph-OLED devices, including hyper-OLEDs and active-matrix (AM) displays.

Main Results:

• Achieved exceptional photoluminescence quantum yields (PLQY) of 98% and decay rate constants of 7.97 × 10^5 s^-1.
• Demonstrated peak external quantum efficiencies (EQE) of 31.62% and high brightness up to 214,255 cd/m^2.
• Exhibited minimal efficiency roll-off, high operational stability (LT50 reaching 1237 h), and narrow FWHM (20 nm) for hyper-OLEDs.

Conclusions:

• The novel Ir(III) emitters represent a significant milestone in advancing blue Ph-OLED technology.
• The developed materials and devices offer superior efficiency, stability, and brightness compared to existing benchmarks.
• The successful fabrication of AM blue Hyper-OLEDs demonstrates their potential for practical application in high-resolution displays.