Photoluminescent Re<sub>6</sub>Q<sub>8</sub>I<sub>2</sub> (Q = S, Se) Semiconducting Cluster Compounds
作者:Craig C. Laing、Jiahong Shen、Daniel G. Chica、Shelby A. Cuthriell、Richard D. Schaller、Chris Wolverton、Mercouri G. Kanatzidis
DOI:10.1021/acs.chemmater.1c01696
日期:2021.7.27
We report three new rhenium chalcohalide cluster compounds, Re6S8I2, Re6S4Se4I2, and Re6Se8I2. The materials crystallize in the three-dimensional (3D) Re6S8Cl2 structure type with the space group P21/n. They can be synthesized with sufficiently large iodine gas pressures or using alkali metal iodide salt fluxes with excess iodine. All three compounds are thermally stable under vacuum up to 1000 °C, and density functional theory (DFT) calculation results predict them to be direct-gap semiconductors. The measured work functions, which are the valence band maxima with respect to vacuum, and the measured band gaps are 5.49(5) and 1.69(5) eV, 5.24(5) and 1.54(5) eV, and 5.03(5) and 1.44(5) eV for Re6S8I2, Re6S4Se4I2, and Re6Se8I2, respectively. They exhibit red to near-IR photoluminescence ranging from 1.38 eV (898 nm) to 1.93 eV (642 nm) centered at 1.67 eV (742 nm) for Re6S8I2 and ranging from 1.35 eV (918 nm) to 1.70 eV (726 nm) centered at 1.49 eV (832 nm) for Re6Se8I2 with average lifetimes of 5.15 and 1.83 ns, respectively.
我们报告了三种新的铼卤化物簇合物:Re6S8I2、Re6S4Se4I2和Re6Se8I2。这些材料以三维(3D)Re6S8Cl2结构类型结晶,空间群为P21/n。它们可以在足够大的碘气压下合成,也可以使用含过量碘的碱金属碘化物盐助熔剂合成。在真空下,所有三种化合物在高达1000°C的温度下都具有热稳定性,密度泛函理论(DFT)计算结果预测它们是直接带隙半导体。测得的功函数(即相对于真空的价带最大值)和测得的带隙分别为5.49(5)和1.69(5)eV、5.24(5)和1.54(5)eV以及5.03(5)和1.44(5)eV,分别适用于Re6S8I2、Re6S4Se4I2和Re6Se8I2。它们表现出从1.38eV(898nm)到1.93eV(642nm)的红光到近红外光致发光,Re6S8I2的中心波长为1.67eV(742nm),Re6Se8I2的中心波长为1.4