Morphology and photoluminescence properties of electrospun microfibers of poly(9-vinylcarbazole)/tris-(8-hydroxyquinoline)aluminum and poly(9-vinylcarbazole)/4,7-diphenyl-1,10-phenanthroline blends

• Green fluorescent electrospun PVK/Alq3 and PVK/Bphen blend fibers were obtained.
• Electrospinnability of the solutions with Bphen was enhanced significantly.
• Electrospun fibers of PVK/Alq3 undergo energy transfer from PVK to Alq3.
• Intensity of the PVK/Alq3 fibers increased up to 9 times compared to Alq3 films.
• Bphen favors formation of fully overlapping, sandwich-like configurations in PVK.

Green fluorescent electrospun fibers of poly(9-vinylcarbazole) (PVK)/tris-(8-quinolinolato)aluminum (Alq3) and PVK/4,7-diphenyl-1,10-phenanthroline (Bphen) with widths on the micrometer scale were successfully obtained from solutions in dichloroethane (DCE). The concentration of the electron-transport molecules (Alq3 or Bphen) was from 0.5 to 60 (wt%). PVK/Alq3 fibers were thick and rough whereas PVK/Bphen fibers were thin and uniform; additionally, the electrospinnability of the solutions with Bphen was enhanced significantly. Studies of photoluminescence (PL) indicate an efficient energy transfer from PVK to Alq3 in electrospun PVK/Alq3 fibers. As for PVK/Bphen fibers, the consistent decrease of the broad PVK emission is mainly attributed to Bphen favoring the formation of fully overlapping, sandwich-like configurations in the PVK. The parallel decrease of the PLE spectra as Bphen increases corroborates the increment in excimer formation.