We are reporting a new synthetic strategy to grow large-sized black phosphorus (Black-P) crystals through a ternary clathrate Sn₂₄P_22–xI₈, under lower synthetic temperature and pressure. The Black-P crystals are found grown in situ at the site where the solid clathrate originally resides, which suggests chemical vapor mineralizer does not play a critical role for the Black-P formation. More detailed systematical studies have indicated the P vacancies in the framework of the ternary clathrate Sn₂₄P_22–xI₈ are important for the subsequent Black-P from phosphorus vapors, and a likely vapor–solid–solid model is responsible for the Black-P crystal growth. The obtained room temperature mobility μ is ∼350 cm²/V·s from Hall measurements at mechanically cleaved flakes, where noticeable microcracks are visible. The obtained high mobility value further suggests the high quality of the Black-P crystals synthesized through this route.

中文翻译：

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通过三元包合物生长黑磷晶体的新策略

我们正在报告一种新的合成策略，该方法可以在较低的合成温度和压力下通过三元笼状Sn ₂₄ P _{22– x} I _8生成大尺寸黑磷（Black-P）晶体。发现Black-P晶体在固体包合物最初所在的位置就地生长，这表明化学气相矿化剂对Black-P的形成没有关键作用。更详细的系统研究表明，三元包合物Sn ₂₄ P _{22– x} I ₈框架内的P空位对于随后的磷蒸气中的Black-P来说非常重要，并且可能的气固固模型是Black-P晶体生长的原因。在机械裂解的薄片上，从霍尔测量得到的室温迁移率μ约为350 cm ² / V·s，在该处可见明显的微裂纹。所获得的高迁移率值进一步暗示了通过该途径合成的Black-P晶体的高质量。