Highly efficient organic electroluminescent devices based on cyclometallated platinum complexes as new phosphorescent emitters

Abstract

High efficiency electroluminescence (EL) in organic light emitting diodes (OLED) was achieved using cyclometallated platinum(II) complexes as new phosphorescent emitters. OLEDs containing bis[2-(2-thienyl)pyridine]platinum(II) [Pt(thpy)2] or bis[2-(5-trimethylsilanyl-2-thienyl)-pyridine]platinum(II) [Pt(thpy-SiMe3)2] show a high external EL quantum yield reaching 5.4 and 11.5% photon/electron, respectively. Both electroluminescent spectra fall in the “amber” color region defined by the automotive lighting standards; specifically the CIE coordinates are (0.58; 0.42) for Pt(thpy)2 and (0.60; 0.39) for Pt(thpy-SiMe3)2.