Abstract Quasi-one-dimensional lead based perovskite CsPbI 3 exhibits increasing interests in quantum dots, solar cells, etc . However, high quality large CsPbI 3 bulk crystals are still unexplored. Here we report CsPbI 3 crystal growth from HI aqueous solution by tailoring the solubility. The morphology and crystal structure of CsPbI 3 are characterized by SEM and XRD, which reveal the stick-like structure with the space group Pnma and lattice parameters a = 10.46 A, b = 4.80 A, and c = 17.78 A. Ultra violet-visible transmission spectra substantiate CsPbI 3 being a direct-gap semiconductor with a band-gap ∼2.69 eV. In addition, a broad emission at 550–580 nm with a large Stokes shift of 0.60 ∼ 0.75 eV and the corresponding dissociation energy 7.58 meV was found using temperature and power dependent PL spectra. This emission was attributed to a strong electron–phonon coupling induced “self-trap excitons” in CsPbI 3 . Our finding shields more light on the crystal growth, structure and optical properties of CsPbI 3 .

中文翻译：

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HI水溶液准一维铅基钙钛矿CsPbI 3 晶体的制备与表征

摘要 准一维铅基钙钛矿CsPbI 3 在量子点、太阳能电池等方面表现出越来越大的兴趣。然而，高质量的大 CsPbI 3 块状晶体仍有待探索。在这里，我们通过调整溶解度来报告从 HI 水溶液中生长的 CsPbI 3 晶体。通过SEM和XRD表征CsPbI 3 的形貌和晶体结构，显示出具有空间群Pnma和晶格参数a = 10.46 A、b = 4.80 A和c = 17.78 A的棒状结构。 紫外可见透射光谱证实 CsPbI 3 是带隙约 2.69 eV 的直接带隙半导体。此外，使用温度和功率相关的 PL 光谱发现了 550-580 nm 的宽发射，具有 0.60 ∼ 0.75 eV 的大斯托克斯位移和相应的解离能 7.58 meV。这种发射归因于 CsPbI 3 中强电子-声子耦合诱导的“自陷激子”。我们的发现屏蔽了更多关于 CsPbI 3 的晶体生长、结构和光学特性的信息。