Organic light-emitting diodes based on an ambipolar single crystal

Slice-like organic single crystals of 1,4-bis(2-cyano-2-phenylethenyl)benzene (BCPEB) are grown by the physical vapor transport (PVT) method, and exhibit a very high photoluminescence quantum efficiency (Phi(PL)) of 75%. The ambipolar behavior of BCPEB single crystals are confirmed using the time of flight technique. The high efficiency and balanced (mu(h) = 0.059 cm(2)/Vs and mu(e) = 0.070 cm(2)/Vs) carriers' mobility imply that the BCPEB single crystal is a promising light-emitting layer in the diodes structure. Intense green electroluminescence (EL) from a diode has been successfully demonstrated at an applied electric field of 2 x 10(5) V/cm. (C) 2012 Elsevier B.V. All rights reserved.