“…23,24 The samples for the measurements were prepared by drop casting of solutions of the compounds in THF onto a polyester film with Al layer. 25 Materials 4-Bromo-2 0 -nitrobiphenyl, 26 2-bromocarbazole, 26 2-bromo-9-ethylcarbazole, 27 2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9-ethylcarbazole, 4,4 0 -dibromo-2-nitrobiphenyl, 16 2,7-dibromocarbazole, 16 2,7-dibromo-9-(2-ethylhexyl)carbazole, 16 2-bromo-9,9-diethylfluorene, 28 2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9,9-diethylfluorene, 28 2,7-dibromo-9,9-di(2-ethylhexyl)fluorene, 29 2,7-dibromo-9,9-dihexylfluorene 30 were prepared according to published procedures.…”