Solid-state Synthesis, Crystal and Band Structures, and Optical Properties of a Novel Ternary Sulfide Eu2Ga2S5

摘要: One new ternary europium gallium sulfide, Eu2Ga2S5, has been synthesized by a facile solid-state route with boron as the reducing reagent. It crystallizes in the orthorhombic space group Pbca, with a = 11.976(1), b = 11.074 (1), c = 17.446(1) � V = 1650.6(3) �, and Z = 8. Its 3-D structure is built by the connection between EuS7 monocapped trigonal prisms and GaS4 tetrahedra, and the latter connect with each other to form layer-like slabs. Its optical energy gap is determined to be 2.17 eV, which is also verified by the electronic band structure calculation.