Thermostable Eu(III)-nanorod luminophores with effective photosensitized energy transfer

Abstract

The thermostable Eu(III)-doped nanorod aggregates composed of luminescent Eu(III) complexes and diphenylphosphinic acids (DPP) are reported. Prepared Eu(III)-nanorod aggregates [Eu(hfa)x(TPPO)y(DPP)z]n (hfa: hexafluoroacetylacetionate, TPPO: triphenylphosphine oxide), Eu(III)-nanoparticle aggregates [Eu(hfa)x(DPP)y]n, and standard Eu(III)-nanoparticles [Eu(DPP)x]n were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements. The decomposition temperatures of [Eu(hfa)x(DPP)y]n and [Eu(hfa)x(TPPO)y(DPP)z]n for thermogravimetric analysis (TGA) were found to be over > 500 °C. Photosensitized luminescence was successfully observed for Eu(III)-nanorod and Eu(III)-nanoparticle aggregates excited at the specific π–π* transition band for organic hfa ligands (λ = 340 nm), which is similar to the inter-ligand charge transfer (ILCT) band in the solid-state, were successfully observed. The photosensitized energy transfer efficiency of Eu(III)-nanorod aggregates of [Eu(hfa)x(TPPO)y(DPP)z]n was estimated to be 91%. In this study, thermostable Eu(III)-nanorod aggregate luminophore composed of Eu(III) complexes and DPP joint compounds are demonstrated.