Computational Study of Magic-Size CdSe Clusters with Complementary Passivation by Carboxylic and Amine Ligands

详细信息    查看全文

• 作者：Oleksandr Voznyy ; Junais Habeeb Mokkath ; Ankit Jain ; Edward H. Sargent ; Udo Schwingenschlögl
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：May 12, 2016
• 年：2016
• 卷：120
• 期：18
• 页码：10015-10019
• 全文大小：404K
• 年卷期：0
• ISSN：1932-7455

文摘

The electronic and optical properties of tetrahedral CdSe magic clusters (average diameter ∼1.5 nm) protected by carboxyl and amine ligands, which correspond to previously reported experimental structures, are studied using density functional theory. We find extreme ligand packing densities, capping every single dangling bond of the inorganic core, strong dependence of the Z-type metal carboxylate binding on the amount of excess amine, and potential for improved photoluminescence upon replacing phenyl ligands with alkanes. The computed absorption spectra of the Cd₃₅Se₂₀ cluster agree well with experiments, resolving the 0.2 eV splitting of the first exciton peak due to spin–orbit coupling. We discuss the origin of the significant broadening of the optical spectra as due to phonons and structural variations in the ligand configurations and inorganic core apexes.