Details

Autor(en) / Beteiligte

• Luo, Xu-Feng
• Ning, Sheng
• He, Hang
• Tang, Hao
• Shen, Liang-Jun
• Shen, Yi-Rui
• Han, Hua-Bo
• Xiao, Xunwen
• Zheng, You-Xuan

Titel

Design of carbazole-based platinum complexes with steric hindrance for efficient organic light-emitting diodes

Ist Teil von

• Dalton transactions : an international journal of inorganic chemistry, 2023-10, Vol.52 (38), p.1367-13676

Ort / Verlag

Cambridge: Royal Society of Chemistry

Erscheinungsjahr

2023

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The construction of platinum complexes with high steric hindrance is expected to suppress triple-triplet annihilation and π-π stacking to achieve high-performance organic light-emitting diodes (OLEDs) with low efficiency roll-off. Herein, two large steric hindrance platinum complexes ( N -CzPhPtacac and N -CzCF 3 PhPtacac) were prepared by taking advantage of steric hindrance between the phenyl group on carbazole and the functional group (phenyl and trifluoromethyl substituted phenyl) at the 3-position of a pyridine moiety. Due to the similar electron cloud distribution and gap difference between the HOMO and LUMO, the two complexes showed similar orange-red emission peaks at 590 and 596 nm with high PL quantum yields of 90% and 92% and short excited state lifetimes of 2.77 and 3.08 μs in doped films, respectively. Consequently, OLEDs based on N -CzPhPtacac and N -CzCF 3 PhPtacac showed maximum external quantum efficiency (EQE max ) values of 15.4% and 18.9%, respectively. Importantly, benefitting from the more stretched spatial configuration from the -CF 3 effect, the corresponding OLED exhibited a lower efficiency roll-off, with an EQE of 18.1% at 1000 cd m −2 . The construction of platinum complexes with high steric hindrance is expected to suppress triplet-triplet annihilation and π-π stacking to achieve high-performance organic light-emitting diodes (OLEDs) with low efficiency roll-off.