Amorphous 2,3-Substituted Thiophenes: Potential Electroluminescent Materials

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 Alq 3 )/Mg:Ag (TPBI = (1,3,5-tris( N -phenylbenzimidazol-2-yl)benzene); Alq 3 = tris(8-hydroxyquinolinato)aluminum) and blue light-emitting device ITO/ 12 /TPBI/Mg:Ag exhibit promising physical performance.