(Dis)Order and Luminescence in Silicon-Rich (Si,P)-N Network SrSiPN:Eu.

In this work, we present the synthesis, characterization, and optical properties of SrSiPN:Eu, the first tetrahedral (Si,P)-N network in which Si occupies more than 50% of the tetrahedra. While past studies have shown progress with anionic (Si,P)-N networks, the potential of silicon-rich compounds remains untapped. The synthesized compound SrSiPN exhibits a unique mixture of substitutional order and positional disorder within its network. The analytical challenges posed by the similarities between Si and P, along with the network's disorder, were overcome by combining single-crystal X-ray diffraction and scanning transmission electron microscopy EDX mapping. Low-cost crystallographic calculations provided additional insights into the identification of tetrahedral occupations in mixed networks. Luminescence investigations on SrSiPN:Eu revealed yellow emission, adding to the known blue, green, and orange emission maxima of Sr-(Si,P)-N networks, highlighting the variability of such compounds.