Luminescent tetraphenylethene-substituted silanes

Tetraphenylethene (TPE)-substitued silanes [(Ph4C=C)(m)Si(Ph)(n), m = 3-1, n = 3-1] are designed and synthesized, and their optical, thermal, and electrochemical properties are studied. Whereas they are nonluminescent in solutions, they become highly emissive when aggregated in poor solvents (such as water) or fabricated into thin films, demonstrating a novel phenomenon of aggregation-induced emission (AIE). Their amorphous films exhibit high fluorescence quantum yields (54.6-63.7 %). They enjoy high thermal stability with 5 % weight loss occurring at 320-420 degrees C. Multi layer electroluminescence (EL) devices (ITO/NPB/emitter/TPBi/LiF/Al) utilizing the silanes as emitting layers are fabricated, which give deep blue EL with maximum luminance and external quantum efficiency of 5672 cd/m(2), and 1.6 %, respectively.