Solution-Processed Organic Light-Emitting Diodes of Yellow-Emitting PtAg2 Complexes with an External Quantum Efficiency of 21.7%

Yellow emission is a complementary color of blue for achieving white emission. Here, we report two yellow-emitting PtAg2 heterotrinuclear complexes (1 and 2) of 4-ethynyl-N,N-diphenylaniline, supported by bis(diphenylphosphinomethyl)-phenylphosphine (dpmp) and bis(di-o-tolylphosphinomethyl)phenylphosphine (dTolmp), respectively. The solution-processed organic light-emitting diode based on complex 1 exhibits yellow emission peaked at 567 nm with the highest current efficiency (CE) of 49.7 cd A(-1) and an external quantum efficiency (EQE) of 14.3%. Remarkably, the device performance of complex 2 containing dTolmp with a larger steric hindrance as the supporting ligand is dramatically enhanced with the CE boosting to 69.1 cd A(-1) and EQE of 21.7% and, more importantly, a better color saturation of yellow emission peaked at 579 nm with the CIE of (0.49, 0.50).

Automated summary

In this study, two yellow-emitting PtAg2 heterotrinuclear complexes were reported, with complex 2 showing significantly enhanced device performance when containing dTolmp as the supporting ligand. The improved performance includes higher current efficiency and external quantum efficiency, as well as better color saturation of yellow emission.