5Cz-TRZ, 9,9',9'',9''',9''''-(6-(4,6-Diphenyl-1,3,5-triazin-2-yl)benzene-1,2,3,4,5-pentayl)pentakis(9H-carbazole), is a highly efficient sky-blue TADF emitter. It consists of five electron donating carbazole and one 4,6-diphenyl-1,3,5-triazine units around a hexagonal benzene ring. 5Cz-TRZ is well known for its fast kRISC of 1.5 × 107 s−1, almost two orders of magnitude higher than those of typical TADF emitters. 5Cz-TRZ has a small singlet–triplet energy splitting, large spin–orbit couplings, and a dense manifold of triplet states energetically close to the singlets.

OLEDs based on 5Cz-TRZ as blue dopant and mCBP as host exhibit high maximum external quantum efficiency of 29.3%, and good device stability with estimated T90 about 600 h for 1,000 cd m-2. Also, 5Cz-TRZ exhibits an extremely low efficiency roll‐off mainly due to the fast rate of reversed intersystem crossing. For example, the efficiency remains at 28.6% at 1000 cd m-2 and still as high as 27.0% at 5000 cd m-2, corresponding to a 2.3% decrease in EQE even at high brightness intensities.

5Cz-TRZ features the following as a TADF material.

• A small energy gap (ΔEST) between its singlet and triplet states
• A high RISC rate of 1.5 ×  107 s−1
• A high ΦPL of 99% (15 wt% mCBP)
• A τd of 0.8 μs in DMF 
  

General Information

Product Details

Chemical Structure

Chemical structure of 5Cz-TRZ, CAS number: 2043597-42-6