Red electroluminescence and photoluminescence properties of a reduced porphyrin compound, tetraphenylchlorin

Abstract

We report red PL and EL properties of a reduced porphyrin, tetraphenylchlorin (TPC). In monomer solution TPC emitted a red PL band at 655 nm. In solid mono-film TPC emitted a red PL band at 660 nm but it also emitted two far-red PL bands at 725 and 750 nm due to aggregated emission sites in the film. EL devices in which TPC were doped at concentrations of 1.6–3.7 wt.% within an Alq 3 host layer showed red EL color due to a 660-nm emission of TPC monomer with a width of 20 nm. The red-emitting devices using α-NPD as a hole-transport layer had maximum luminance higher than those using TPD did. Among the red devices, we obtained a maximum luminance of 520 cd/m 2 with chromaticity coordinates of x=0.620 and y=0.31.