New phosphorescent platinum(ii) Schiff base complexes for PHOLED applications

Some new symmetric and asymmetric platinum(II) Schiff base complexes with bulky substituents such as tert-butyl and triphenylamino groups have been synthesized which effectively reduced the aggregation or excimer formation. Using selected complexes as phosphorescent emitting materials, yellow light-emitting devices were fabricated with improved efficiency compared with the previously reported analogues. In addition, the phosphorescent white organic light-emitting device (WOLED) was fabricated using a single emissive layer composed of yellow- and blue-emitting materials.