Butterfly-Shaped Thiophene-Pyridine Hybrids: Green Electroluminescence And Large Third-Order Optical Nonlinearities

A set of four symmetric, butterfly-shaped 4-(4-(decyloxy)phenyl)-2,6-di(thiophen-2-yl)pyridine (TPY) derivatives2TPA-TPY(TPY center and triphenylamine end groups),2CBZ-TPY(TPY center and N-ethyl carbazole end groups),2TPY-TPA(triphenylamine center and TPY at the periphery) and2TPY-CBZ(N-ethyl carbazole center and TPY at the periphery) was synthesized. The molecules show reverse saturable absorption (RSA) which is consistent with two-photon absorption (2PA) associated with excited-state absorption (ESA) when excited using a 532 nm laser beam. The molecules2TPA-TPYand2TPY-TPApossess extremely low limiting thresholds of 1.73 and 2.68 J cm(-2), respectively. An organic light-emitting diode (OLED) fabricated from2TPA-TPYexhibits green emission with a maximum luminance of 207 cd m(-2), a current efficiency (eta(CE)) of 1.51cd A(-1), a maximum power efficiency (eta(Pmax)) of 0.46 lm W(-1)and an external quantum efficiency (eta(EQE)) of 0.48 % at 100 cd m(-2).