Abstract
Summary: We have designed and synthesized novel diphenylamine‐substituted phenylazomethine dendrimers (DP‐G__n__, n = 1, 2) as hole‐transport materials for organic light‐emitting diodes (OLEDs). These dendrimers similar to phenylazomethine dendrimers showed a stepwise metal complexation with metal ions. They have good multi‐redox properties attributed to the terminal amine moieties and excellent thermal stabilities. Double layer EL devices utilizing the dendrimers as a hole‐transport material and Alq~3~ as the emitting and electron transport materials were fabricated. The EL performances of the devices increased with higher dendrimer generations. Moreover, by using the metal ion (0.5 equiv. SnCl~2~)‐complexed DP‐G2 dendrimers, the luminance and EL efficiency of the devices were drastically increased by more than double and over 30%, respectively. These metal complexable phenylazomethine dendrimers are novel and promising materials for highly efficient OLEDs.
Structure of the diphenylamine‐substituted phenylazomethine dendrimer DP‐G2.
magnified imageStructure of the diphenylamine‐substituted phenylazomethine dendrimer DP‐G2.