title: Active layer solution-processed NIR-OLEDs based on ternary erbium(III) complexes with 1,1,1-trifluoro-2,4-pentanedione and different N,N-donors.
abstract: Using a fluorinated 1,1,1-trifluoro-2,4-pentanedione (Htfac) ligand and either 2,2'-bipyridine (bipy), bathophenanthroline (bath) or 5-nitro-1,10-phenanthroline (5NO2phen) as an ancillary ligand, three new ternary erbium(iii) octacoordinated complexes have been synthesized. The single crystal structures of the new complexes (namely [Er(tfac)3(bipy)], [Er(tfac)3(bath)] and [Er(tfac)3(5NO2phen)]) have been determined and their properties have been investigated by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and thermodynamic analysis. After ligand-mediated excitation of these complexes in the UV, they all show the characteristic near-infrared (NIR) luminescence of the corresponding Er(3+) ion at 1532 nm. The same emission in the C-band transmission window can also be obtained from the solution-processed organic light-emitting diodes (OLEDs) with structure: glass/ITO/PEDOT:PSS/[Er(tfac)3(N,N-donor)]/Ca/Al. In spite of the fact that the photoluminescence intensity of [Er(tfac)3(5NO2phen)] is stronger than those of [Er(tfac)3(bipy)] and [Er(tfac)3(bath)], the best electroluminescence results correspond to the OLED based on the [Er(tfac)3(bath)] complex, as a consequence of the superior electron transport capabilities of bathophenanthroline.
authors.affiliation: Advanced Materials Laboratory, ETSIIAA, Universidad de Valladolid, Avenida de Madrid 44, 34004, Palencia, Spain. mgil@iaf.uva.es.
authors.forename: P
authors.initials: P
authors.lastname: Martín-Ramos
authors.forename: C
authors.initials: C
authors.lastname: Coya
authors.forename: V
authors.initials: V
authors.lastname: Lavín
authors.forename: I R
authors.initials: IR
authors.lastname: Martín
authors.forename: M Ramos
authors.initials: MR
authors.lastname: Silva
authors.forename: P S Pereira
authors.initials: PS
authors.lastname: Silva
authors.forename: M
authors.initials: M
authors.lastname: García-Vélez
authors.forename: A L
authors.initials: AL
authors.lastname: Alvarez
authors.forename: J
authors.initials: J
authors.lastname: Martín-Gil