Rybak, Jens-ChristophJens-ChristophRybakHailmann, MichaelMichaelHailmannMatthes, Philipp R.Philipp R.MatthesZurawski, AlexanderAlexanderZurawskiNitsch, JörnJörnNitschSteffen, AndreasAndreasSteffenHeck, Joachim G.Joachim G.HeckFeldmann, ClausClausFeldmannGötzendörfer, StefanStefanGötzendörferMeinhardt, JürgenJürgenMeinhardtSextl, GerhardGerhardSextlKohlmann, HolgerHolgerKohlmannSedlmaier, Stefan J.Stefan J.SedlmaierSchnick, WolfgangWolfgangSchnickMüller-Buschbaum, KlausKlausMüller-Buschbaum2022-03-042022-03-042013https://publica.fraunhofer.de/handle/publica/23238110.1021/ja31217182-s2.0-84877255106The rare case of a metal-triggered broad-band yellow emitter among inorganic-organic hybrid materials was achieved by in situ codoping of the novel imidazolate metal-organic framework 3[Ba(Im)2] with divalent europium. The emission maximum of this dense framework is in the center of the yellow gap of primary light-emitting diode phosphors. Up to 20% Eu2+ can be added to replace Ba2+ as connectivity centers without causing observable phase segregation. High-resolution energy-dispersive X-ray spectroscopy showed that incorporation of even 30% Eu2+ is possible on an atomic level, with 2-10% Eu2+ giving the peak quantum efficiency (QE = 0.32). The yellow emission can be triggered by two processes: direct excitation of Eu2+ and an antenna effect of the imidazolate linkers. The emission is fully europium-centered, involving 5d ? 4f transitions, and depends on the imidazolate surroundings of the metal ions. The framework can be obtained by a solvent-free in situ approach starting from barium metal, europium metal, and a melt of imidazole in a redox reaction. Better homogeneity for the distribution of the luminescence centers was achieved by utilizing the hydrides BaH2 and EuH2 instead of the metals.en666540journal article