Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße 4, 35032, Marburg, Germany.
Department of Physics, Philipps-University Marburg, Renthof 5, 35032, Marburg, Germany.
Chempluschem. 2023 Jun;88(6):e202200403. doi: 10.1002/cplu.202200403. Epub 2023 Apr 5.
Lead-free heavy halogenido metalates are currently under intense investigation, as they show similarly promising semiconducting properties as their famous but toxic lead relatives. A major interest in this regard is the understanding and control of optical properties with the goal of designing highly efficient photoconducting materials. Here, we present two isostructural iodido pentelates (Hpyz) E I ⋅ 2H O (pyz=pyrazine; E=Sb, Bi). Both compounds are stable up to 100 °C. We observe an inverted order of band gap sizes, 1.91 eV and 1.98 eV for the antimony and bismuth compound, respectively, compared to similar pairs of compounds. We use DFT calculations to confirm that this surprising finding can be traced back to the presence of charge transfer excitations in both compounds.
无铅重卤素金属酸盐目前受到了强烈关注，因为它们表现出与著名但有毒的铅同系物类似的有前景的半导体性质。在这方面的一个主要兴趣是理解和控制光学性质，以设计高效的光电导材料。在这里，我们展示了两种同构的碘代五唑金属酸盐（Hpyz）E I ⋅ 2H O（pyz=吡嗪；E=Sb，Bi）。这两种化合物在 100°C 下都稳定。我们观察到带隙尺寸的顺序颠倒，分别为 1.91 eV 和 1.98 eV，对于锑和铋化合物，与类似的化合物对相比。我们使用 DFT 计算来证实这一令人惊讶的发现可以追溯到两种化合物中都存在电荷转移激发。
