Monodisperse CdSe@CdS dot@platelet quantum dots (QDs), free of stacking faults, are synthesized for formation of the peanut-shaped homodimers connected by an epitaxial neck ( p -dimers). Instead of attachment along the wurtzite ⟨11 2 0⟩ axis of QDs with stacking faults, the stacking-fault-free QDs attach to each other along the wurtzite ⟨10 1 0⟩ axis. Furthermore, the reaction system enables in situ epitaxial neck-filling to form rodlike homodimers ( r -dimers). The resulting p -dimers and r -dimers are monodisperse in size, inter-QD connecting dimension (i.e., neck or filled neck), and QD-QD alignment, allowing resolution of energy gap between bonding and antibonding levels at an ensemble level. Formation of r -dimers not only enhances quantum coupling between two epitaxially attached QDs but also augments optical properties of artificial diatomic molecules. These advancements pave the way for the solution-phase synthesis of high-quality artificial molecules for fundamental research and technical applications.
Qin et al. (Sun,) studied this question.