Molecular Weight Engineering of Host Materials for Overall Device Performance in Multi-resonance TADF OLEDs
발표자
김신영 (고려대학교)
연구책임자
최동훈 (고려대학교)
초록
내용
In this study, we investigated the effect of host materials with different molecular weights (MWs) on OLED performance, using a fixed conjugated core unit, CzCzPh. Three hosts were synthesized: CzCzPh-mAd (low-MW), Cy-2(Ph-mCzCz) (medium-MW), and P(Ph-mCzCz) (high-MW). Despite similar energy levels, high triplet energies across all hosts, device performance varied significantly. We also synthesized a solution-processable blue multi-resonance (MR) emitter, 4FlDABNA, with narrow-band emission and high solubility. To assess host universality, a device using the sky-blue emitter 5TCzBN was also fabricated. OLEDs with low- and medium-MW hosts outperformed those with the high-MW polymer host. Notably, Cy-2(Ph-mCzCz) demonstrated stable performance even under high-temperature drying, indicating that the medium-MW host offers an optimal balance of molecular stability, film morphology, and efficiency. These findings highlight its potential as a universal host.