Amorphous 2,3-Substituted Thiophenes:  Potential Electroluminescent Materials

Abstract

Amorphous 2,3-disubstituted thiophenes and 2,3,5-trisubstituted thiophenes which contain two and four peripheral triarylamine moieties, respectively, have been synthesized and characterized. The compounds are weakly to moderately fluorescent with a lifetime of ∼1 ns. Double-layer devices were fabricated using 2,3-bis{5‘-[4‘ ‘-(diphenylamino)phenyl]-2‘-thienyl}thiophene (10) or 2,3-bis{4-[4‘((1-naphthyl)(phenyl)amino)-p-biphenyl]thiophene (12) as hole-transport as well as emitting materials. Both green light-emitting device ITO/10/TPBI (or Alq3)/Mg:Ag (TPBI = (1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene); Alq3 = tris(8-hydroxyquinolinato)aluminum) and blue light-emitting device ITO/12/TPBI/Mg:Ag exhibit promising physical performance.