A series of donor–acceptor type ambipolar electroluminescence dyes with the general structure PQ(OXD) n T (where n=1, 2 and 3) were prepared, in which PQ is 2-phenylquinoline, T is diphenylamine which constituted the hole transporting triphenylamine moiety with an adjacent phenyl ring, and OXD is an electron transporting 2-phenyl-1,3,4-oxadiazole repeating unit. The compounds fluoresced bluish green to green hue in solid-state, exhibited a positive solvatochromism in solution and their quantum efficiency decreased rapidly with increase in n. The materials are thermally stable with glass transition temperature (T g ) ranging from 83°C (n=1) to 130°C (n=3). Cyclic voltammetry studies indicated the HOMO remained relatively unchanged with n while the LUMO decreased (away from the vacuum level) with an increase in the number of OXD. For single layer homojunction OLEDs, highest efficiency was obtained when n=1 (max luminous 3300cd/m 2 and current efficiency 0.9cd/A), whereas for multilayer heterojunction OLEDs, best results was achieved for compounds with n=1 or 2 assuming the role of the HT layer (over 8200cd/m 2 max and 2.0cd/A). Formation of exciplexes led to significant red-shift and lower emission efficiency for the compound with n=3.