A Rigid Tetradentate Pt(II) Complex for Ultrastable Green OLED with Microcavity-Enhanced Color Purity

Achieving simultaneously high color purity and long operational lifetime in organic light-emitting diodes (OLEDs) remains a major challenge for next-generation displays. Herein, we report a rigid tetradentate Pt(II) complex, Pt-ONP, rationally designed by extending π-conjugation and increasing steric hindrance. Benefiting from constructive Fabry-Pérot interference, the top-emitting OLED (TE-OLED) based on Pt-ONP exhibits pure green emission with a peak at 526 nm, a small full-width at half-maximum (FWHM) of 28.6 nm, and Commission Internationale de l'Eclairage (CIE) coordinates of (0.246, 0.713). The TE-OLED also shows high current efficiency (120.0 cd/A) and, notably, unprecedented operational stability. Accelerated lifetime modeling gives an estimated LT90 of over 225,000 h at 1000 cd/m2─the longest lifetime reported for pure-green OLED (CIEy ≥0.70) to date, exceeding previous records by approximately 18-fold. These results highlight the synergistic impact of molecular rigidification and microcavity engineering, establishing Pt-ONP as a promising emitter for next-generation displays.