Color tuning of doped PLEDs by energy transfer from PVK to dopant constituted with biphenyl and butadienyl unit

Abstract

A dopant, 4,4'-bis(dimethyl[4-(2-phenyl-buta-1,3-dienyl)phenyl]amine) biphenyl (BPAB), was synthesized, and single layered polymer light emitting diode (PLED)s, ITO/Host:Dopant/Al, were fabricated with blends of poly(vinyl carbazole) (PVK) as host and BPAB as dopant. The electroluminescence (EL) was observed in doped PLEDs. From the EL and photoluminescence (PL) spectra, the existence of energy transfer from host to dopant was verified. With increasing content of dopant (BPAB), blue emission originated from PVK reduced, but didn't completely disappear, suggesting inefficient energy transfer from PVK to BPAB. When the content of BPAB was 15 wt%, yellow green emission from PLED was observed due to partial energy transfer from PVK to BPAB.