Large Semiconductor Molecules

Single-Crystal and Electronic Structure of a 1.3 nm Indium Phosphide Nanocluster

“…A longstanding challenge in this field has been to prepare a homogeneous sample and to grow a single crystal in order to determine a high-resolution structure that allows for unambiguous assignment of these three properties. While there is a rich history of structural interrogation of transition metal and main group cluster molecules, − to date a complete, atomically precise structural picture of a binary semiconductor QD remains elusive.…”

Main-Group-Semiconductor Cluster Molecules as Synthetic Intermediates to Nanostructures

“…Main-group-semiconductor clusters are a class of well-defined molecular species that are intermediate in size between traditional small molecules and larger nanocrystals (Figure ). The synthesis and spectroscopic characterization of such atomically well-defined clusters is of fundamental interest because of their unique photophysical properties, which are unlike either discrete molecular units or the corresponding bulk materials. Many studies have suggested that such cluster species may exist on a continuum with quantum-confined semiconductor nanocrystals with respect to both their electronic and vibrational structure. − This is exciting because such clusters lack the defect-ridden surfaces and inhomogeneous line broadening caused by sample polydispersity, allowing atomically precise clusters to act as an excellent model for exploring structure–function relationships and mechanistic questions within the field of colloidal semiconductor quantum dot (QD) chemistry.…”

“…Main-group-semiconductor cluster molecules have been prepared selectively and have also been isolated from reactions designed to generate colloidal solutions of semiconductor nanomaterials. Many main-group-semiconductor cluster molecules have been structurally characterized in general. ,− However, the synthesis and structural characterization of so-called magic-sized clusters (MSCs) (i.e., atomically precise clusters with elevated thermodynamic stability relative to other cluster sizes/structures that are often implicated as intermediates to larger nanostructures) is rare. , Our laboratory became interested in such clusters because of their apparent impact on the synthesis of indium phosphide QDs. Specifically, we found that growth of InP QDs could be interrupted at temperatures lower than those used in QD growth, resulting in the isolation of stable magic-sized InP clusters and providing temporally distinct growth regimes for MSCs and QDs .…”

“…Main-group-semiconductor clusters are a class of well-defined molecular species that are intermediate in size between traditional small molecules and larger nanocrystals (Figure 1). 1 The synthesis and spectroscopic characterization of such atomically well-defined clusters is of fundamental interest because of their unique photophysical properties, which are unlike either discrete molecular units or the corresponding bulk materials. Many studies have suggested that such cluster species may exist on a continuum with quantum-confined semiconductor nanocrystals with respect to both their electronic and vibrational structure.…”

Crystalline Superlattices of Nanoscopic CdS Molecular Clusters: An X-ray Crystallography and111Cd SSNMR Spectroscopy Study

“…Metal chalcogenide ME nanoclusters (where M = metal, E = group 16 element heavier than oxygen) continue to be the focus of attention within inorganic chemistry, materials science, and nanoscience because of their size-dependent electronic and optical properties due to quantum confinement effects. − Since many such organic ligand-stabilized metal chalcogenide nanoclusters can be prepared and isolated as single crystals (i.e., ordered superlattices), it is possible to probe their structural features at the atomic level by X-ray crystallography and to correlate structure–property relationships. , Molecular metal chalcogenide nanoclusters of well-defined size, chemical composition, and structure can contain tens to hundreds of metal core atoms, reaching several nanometers in size. − This means that the dimensions of large metal chalcogenide nanoclusters overlap with those of some colloidal nanoparticles . In the case of nanoclusters, polydispersity and structure ambiguityoften inherent to colloidal nanoparticlesare absent.…”