Basu Arghyadeep, Rafisiman Nathan, Shaek Saar, Lifer Rachel, Yadav Vivek, Kauffmann Yaron, Bekenstein Yehonadav, Chuntonov Lev
Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Haifa 3200003, Israel.
Faculty of Material Science and Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel.
J Chem Phys. 2024 May 7;160(17). doi: 10.1063/5.0200873.
Functionalization of perovskite nanocrystal surfaces with thiocyanate anions presents a transformative approach to enhancing stability and photoluminescence quantum yield (PLQY) through surface defect passivation. This study investigates the role of thiocyanate ligands in modifying the optoelectronic properties of CsPbBr3 nanocrystals. We employed ultrafast two-dimensional infrared spectroscopy to investigate the nature of the dynamic interaction of thiocyanate ligands with nanocrystal surfaces, providing insights into the mechanisms underlying the observed increase in PLQY and stability. Our analysis reveals that the thiocyanate ligands efficiently passivate the surface defects, thereby enhancing the PLQY and the stability of the treated nanocrystals. The spectroscopic evidence supports a model where thiocyanate binds to under-coordinated lead atoms, contributing to a stable nanocrystal surface with enhanced optoelectronic performance. This ligand-induced passivation mechanism advances our understanding of surface chemistry's role in optimizing nanomaterials for solar cell and LED applications.
用硫氰酸根阴离子对钙钛矿纳米晶体表面进行功能化，是一种通过表面缺陷钝化来提高稳定性和光致发光量子产率（PLQY）的变革性方法。本研究探讨了硫氰酸根配体在修饰CsPbBr3纳米晶体光电性质中的作用。我们采用超快二维红外光谱来研究硫氰酸根配体与纳米晶体表面动态相互作用的本质，从而深入了解所观察到的PLQY和稳定性增加背后的机制。我们的分析表明，硫氰酸根配体有效地钝化了表面缺陷，从而提高了处理后纳米晶体的PLQY和稳定性。光谱证据支持了一个模型，即硫氰酸根与配位不足的铅原子结合，有助于形成具有增强光电性能的稳定纳米晶体表面。这种配体诱导的钝化机制增进了我们对表面化学在优化用于太阳能电池和发光二极管应用的纳米材料中所起作用的理解。
