Synthesis of Styryl-Terminated Silicon Quantum Dots: Reconsidering the Use of Methanol

摘要

Quantum dot solids, in which individual quantum dots (QDs) such as CdSe, PbSe, and InP QDs are assembled into 3 dimensions, have been paid much research interest due to their potential applicability to diverse optoelectronic fields. Silicon QDs whose electric transitions are direct-like due to the relaxation of k conservation rule are hopeful to replace these QDs owing to its non-toxicity, abundance, and easy integrating into the widely developed silicon industries. Solution processes are preferred for the generation of these solids due to the low cost and large area capability. A post ligand exchange and/or thermal annealing is necessary to enhance physical interactions and electronic communications among the individual QDs. However, in the cases of Si QDs, the post ligand exchange is inapplicable due to the strong covalent bonds between the dot and the capping molecules. Therefore, capping Si QDs with organic molecules has to be logically designed during the synthetic course not only to prevent the Si QDs from unexpected oxidation and give high solubility but also to ensure sufficient QD-QD physical interactions for the solid assemblies.