Fluorescent semiconductor nanocrystals (quantum dots) have the potential to revolutionize biological imaging, but their use has been limited by difficulties in obtaining nanocrystals that are biocompatible. To address this problem, we encapsulated individual nanocrystals in phospholipid block-copolymer micelles and demonstrated both in vitro and in vivo imaging. When conjugated to DNA, the nano...

III-V semiconductor nanocrystals are of considerable interest due to their extensive applications in the optoelectronic and biomedical fields. In order to meet the practical use, the convenient and scalable production of III-V narrow-disperse nanocrystals is inspiring. We report an efficient and rapid method of preparing InP nanocrystals using a wetchemical redox synthetic approach with a nonco...

Chemical reductants of sub-conduction-band potentials are demonstrated to induce large photoluminescence enhancement in colloidal ZnSe-based nanocrystals. The photoluminescence quantum yield of colloidal Mn(2+)-doped ZnSe nanocrystals has been improved from 14% to 80% simply by addition of an outer-sphere reductant. Up to 48-fold redox brightening is observed for nanocrystals with lower startin...

Hybrid nanostructures are interesting materials for numerous applications in chemistry, physics, and biology, due to their novel properties and multiple functionalities. Here, we present a synthesis of metal–semiconductor hybrid nanostructures composed of nontoxic I-III-VI semiconductor nanoparticles and gold. Copper indium sulfide selenide (CuInSSe) nanocrystals with zinc blende structure and ...

The photo-induced enhancement of second harmonic generation and the effect of nanocrystal shape and pump intensity on confined acoustic phonons in semiconductor nanocrystals have been investigated with time-resolved scattering and absorption measurements. The second harmonic signal showed a sublinear increase of the second-order susceptibility with respect to the pump pulse energy, indicating a...

We present theoretical and experimental investigations of the magnetism of paramagnetic semiconductor CdSe:Mn nanocrystals and propose an efficient approach to the exposure and analysis of the underlying anti-ferromagnetic interactions between magnetic ions therein. A key advance made here is the development of an analysis method with the exploitation of group theory technique that allows us to...

Particle size is widely used to tune the electronic, optical, and catalytic properties of semiconductor nanocrystals. This contrasts with bulk semiconductors, where properties are tuned based on composition, either through doping or through band gap engineering of alloys. Ideally, one would like to control both size and composition of semiconductor nanocrystals. Here, we demonstrate production ...

We have developed a code for the detailed simulation of nanocrystal Flash memories, which consist of metal–oxide–semiconductor field-effect transistors ~MOSFETs! with an array of semiconductor nanocrystals embedded in the gate dielectric. Information is encoded in the MOSFET threshold voltage, which depends on the amount of charge stored in the nanocrystal layer. Nanocrystals are charged throug...

The highly organized structure of M13 bacteriophage was used as an evolved biological template for the nucleation and orientation of semiconductor nanowires. To create this organized template, peptides were selected by using a pIII phage display library for their ability to nucleate ZnS or CdS nanocrystals. The successful peptides were expressed as pVIII fusion proteins into the crystalline cap...

The semiconductor CdS is generally found in the wurtzite structure. Prior experimental and theoretical results confirm that the semiconductor CdS nanoparticles maintain a wurtzite structure for diameters greater than 6 nm. There is disagreement in the literature for sizes smaller than 6 nm. We use the density-functional theory FIREBALL code and perform finite-temperature molecular dynamics simu...