Electron Transport Materials: Synthesis, Properties and Device Performance

We report the design, synthesis and characterization, thermal and photophysical properties of two silane based electron transport materials, dibenzo[b,d]thiophen-2-yltriphenylsilane (Si?87) and (dibenzo[b,d]thiophen-2-yl)diphenylsilane (Siφ88) and their performance in blue organic light emitting devices (OLEDs). The utility of these materials in blue OLEDs with iridium (III) bis[(4,6-difluorophenyl)-pyridinato-N,C2’]picolinate (Firpic) as the phosphorescent emitter was demonstrated. Using the silane Siφ87 as the electron transport material (ETm), an EQE of 18.2% was obtained, with a power efficiency of 24.3 lm/W (5.8V at 1 mA/cm2), in a heterostructure. When Siφ88 is used, the EQE is 18.5% with a power efficiency of 26.0 lm/W (5.5V at 1 mA/cm2).