Zero-dimensional organic–inorganic hybrid metal halides are unique semiconductors with fruitful physical properties. Usually, only the inorganic polyhedrons dominate the band edge electronic and photophysical properties of such hybrid semiconductors, whereas the organic components mainly act as structure-stabilizing units. Herein, we study the electronic structures and photodynamics of isoelectronically Br-substituted (I) zero-dimensional organic–inorganic copper halide semiconductors (C9H14N)3Cu3(BrxI1−x)6. They are composed of both inorganic [Cu3(BrxI1−x)6]3− units and organic C9H14N+ skeletons. It is surprising to find that unlike usual organic–inorganic metal halides, although the heavily isoelectronic substitution of halogen atoms in the (C9H14N)3Cu3I6 crystal leads to significant shrinkage of the lattice, it does not remarkably alter the bandgap and luminescence peak owing to the site-projected density of states as revealed by the density functional theory calculation. The inorganic units dominate the valence band edge quantum states, whereas the organic skeletons dominate the conduction-band edge states. However, the isoelectronic substitution significantly lowers the symmetry of the crystal, and as a result, the quantum transition probability at the band edge increases first and decreases then with increasing concentration of substituting bromine atoms. The (C9H14N)3Cu3(BrxI1−x)6 crystals exhibit dual-band luminescence with large Stokes shift and near-unity quantum yield. It arises from the excitons trapped by two kinds of centers. The critical participation of the organic skeletons in the electronic structures and band edge photodynamics refresh our knowledge of their roles in the hybrid semiconductors.

中文翻译：

---

无机/有机亚晶格在等电子取代的混合半导体的带边光动力学中的作用


零维有机-无机杂化金属卤化物是独特的半导体，具有丰富的物理特性。通常，只有无机多面体主导这种混合半导体的带边电子和光物理特性，而有机成分主要充当结构稳定单元。在此，我们研究了等电子 Br 取代 （I） 零维有机-无机卤化铜半导体 （C9H14N）3Cu3（BrxI1−x）6 的电子结构和光动力学。它们由无机 [Cu3（BrxI1−x）6]3− 单元和有机 C9H14N+ 骨架组成。令人惊讶的是，与通常的有机-无机金属卤化物不同，尽管 （C9H14N）3Cu3I6 晶体中卤素原子的重等电子取代导致晶格显着收缩，但由于密度泛函理论计算所揭示的态的位点投射密度，它不会显着改变带隙和发光峰。无机单元主导价带边缘量子态，而有机骨架主导导带边缘态。然而，等电子取代显著降低了晶体的对称性，因此，随着取代溴原子浓度的增加，能带边缘的量子跃迁概率首先增加，然后降低。（C9H14N）3Cu3（BrxI1−x）6 晶体表现出双带发光，具有较大的斯托克斯位移和接近统一的量子产率。它产生于由两种中心捕获的激子。有机骨架在电子结构和带边光动力学中的关键参与刷新了我们对它们在混合半导体中的作用的认识。