Roth Alison N, Porter Andrew P, Horger Sarah, Ochoa-Romero Kerly, Guirado Gonzalo, Rossini Aaron J, Vela Javier
Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States.
US DOE Ames National Laboratory, Ames, Iowa 50011, United States.
Chem Mater. 2024 Apr 19;36(9):4542-4552. doi: 10.1021/acs.chemmater.4c00209. eCollection 2024 May 14.
Tin-based semiconductors are highly desirable materials for energy applications due to their low toxicity and biocompatibility relative to analogous lead-based semiconductors. In particular, tin-based chalcohalides possess optoelectronic properties that are ideal for photovoltaic and photocatalytic applications. In addition, they are believed to benefit from increased stability compared with halide perovskites. However, to fully realize their potential, it is first necessary to better understand and predict the synthesis and phase evolution of these complex materials. Here, we describe a versatile solution-phase method for the preparation of the multinary tin chalcohalide semiconductors SnSbSI, SnBiSI, SnBiSI, and SnSI. We demonstrate how certain thiocyanate precursors are selective toward the synthesis of chalcohalides, thus preventing the formation of binary and other lower order impurities rather than the preferred multinary compositions. Critically, we utilized Sn ssNMR spectroscopy to further assess the phase purity of these materials. Further, we validate that the tin chalcohalides exhibit excellent water stability under ambient conditions, as well as remarkable resistance to heat over time compared to halide perovskites. Together, this work enables the isolation of lead-free, stable, direct band gap chalcohalide compositions that will help engineer more stable and biocompatible semiconductors and devices.
与类似的铅基半导体相比，锡基半导体因其低毒性和生物相容性，成为能源应用中非常理想的材料。特别是，锡基卤硫属化合物具有的光电特性，非常适合用于光伏和光催化应用。此外，与卤化物钙钛矿相比，它们被认为具有更高的稳定性。然而，要充分发挥其潜力，首先需要更好地理解和预测这些复杂材料的合成及相演变。在此，我们描述了一种通用的溶液相方法，用于制备多元锡卤硫属化合物半导体SnSbSI、SnBiSI、SnBiSI和SnSI。我们展示了某些硫氰酸盐前驱体如何对卤硫属化合物的合成具有选择性，从而防止形成二元及其他低阶杂质，而非生成优选的多元组成。至关重要的是，我们利用锡的固体核磁共振光谱进一步评估了这些材料的相纯度。此外，我们验证了锡卤硫属化合物在环境条件下表现出优异的水稳定性，并且与卤化物钙钛矿相比，随着时间推移具有显著的耐热性。总之，这项工作能够分离出无铅、稳定、直接带隙的卤硫属化合物组成，这将有助于设计出更稳定且生物相容的半导体及器件。
