Related Experiment Video
Updated: Apr 15, 2026
Synthesis of In37P20O2CR51 Clusters and Their Conversion to InP Quantum Dots
Published on: May 7, 2019
Environmental Polarity Regulating Development of Magic-Size Clusters and Quantum Dots from CdTe Prenucleation
Yuqi Liu1, Kui Yu1, Yusha Yang1
1Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China.
Abstract:
How to suppress the development of magic-size clusters (MSCs) in reactions of colloidal semiconductor quantum dots (QDs) remains an outstanding challenge. Using the reaction of Cd(OAc)2/OLA (made from cadmium acetate and oleylamine) and TeTOP (tri-n-octylphosphine telluride) as a model system, we show that when tri-n-octylamine (TOA) was used as a reaction medium, MSCs did not form, but QDs did. When OLA was used, MSCs and QDs evolved together. To explain the effect of reaction media, we suggest that prenucleation clusters (PNCs) form first via chemical self-assembly of Cd(OAc)2/OLA and TeTOP. Afterward, the PNC-QD and/or PNC-MSC transformation occurs. The former is favored by a less polar environment (TOA), while the latter by a more polar environment (OLA). Paving the avenue to the inhibition of MSCs in the QD synthesis, this work brings deeper insight into the two-step model, showing that the reaction medium affects the formation and transformation of the PNC.
Related Concept Videos
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than...
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...