Triphenylamine-Dendronized Pure Red Iridium Phosphors with Superior OLED Efficiency/Color Purity Trade-Offs

摘要

Since the first synthesis of red-phosphorescent metal complexes for use in highly efficient organic light-emitting diodes (OLEDs),[1] the scope and diversity of studies on metal-organic phosphors in color tuning have continued to expand at an exponential rate.[2], [3] While great success has been achieved in green-light phosphors, the design and synthesis of efficient red emitters is intrinsically more difficult, in accordance with the energy-gap law.[4] Many red organic dyes currently in use do not show a good compromise between device efficiency and color purity because of the nature of red-light emitters.[4] Typically, efficient and bright dopants are not red enough, and red-enough dopants are not efficient and bright. Optimization of the OLED efficiency/color purity trade-offs is therefore a key consideration for the realization of highly efficient phosphors of good color purity for pure red OLEDs.