A nanocrystal capable of light emission includes a nanoparticle having photoluminescence having quantum yields of greater than 30%.

Highly luminescent color-selective nanocrystalline materials

The present invention provides a composition comprising fluorescent semiconductor nanocrystals associated to a compound, wherein the nanocrystals have a characteristic spectral emission, wherein said spectral emission is tunable to a desired wavelength by controlling the size of the nanocrystal, and wherein said emission provides information about a biological state or event.

Biological applications of quantum dots

A semiconductor nanocrystal compound and probe are described. The compound is capable of linking to one or more affinity molecules. The compound comprises (1) one or more semiconductor nanocrystals capable of, in response to exposure to a first energy, providing a second energy, and (2) one or more linking agents, having a first portion linked to the one or more semiconductor nanocrystals and a second portion capable of linking to one or more affinity molecules. One or more semiconductor nanocrystal compounds are linked to one or more affinity molecules to form a semiconductor nanocrystal probe capable of bonding with one or more detectable substances in a material being analyzed, and capable of, in response to exposure to a first energy, providing a second energy. Also described are processes for respectively: making the semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and treating materials with the probe.

Semiconductor nanocrystal probes for biological applications and process for making and using such probes

We have observed a darkening effect and the formation of permanent volume gratings in CdSSe semiconductor-doped glasses, both phenomena being certainly due to the same photochemical mechanism. This allowed us to reconcile contradictory results concerning the speed of their nonlinear response. We also studied the frequency dependence of X (3) below the gap and the intensity dependence of the reflectivity of these phase-conjugate mirrors. Our results can be interpreted in terms of the band-filling model with Boltzmann statistics. Finally, frequency- and. time-resolved luminescence measurements helped us to interpret various results.

New results on optical phase conjugation in semiconductor-doped glasses

A method of manufacturing a nanocrystallite from a M-containing salt forms a nanocrystallite. The nanocrystallite can be a member of a population of nanocrystallites having a narrow size distribution and can include one or more semiconductor materials. Semiconducting nanocrystallites can photoluminesce and can have high emission quantum efficiencies.

Preparation of nanocrystallites

Fast switching of the transmission of light by glasses activated with CdS microcrystals

Rapid processes of darkening and bleaching in CdS doped glasses

Dynamics of nonlinear optical response of CuBr-doped glasses

Transient effects in photoexcited CdS microcrystals

The nonlinear absorption of CuBr nanocrystals embedded in a transparent glass matrix was investigated by using the excite-and-probe method. The luminescence properties of samples with different average nanocrystal radii were also studied. A fast-decaying damping of exciton absorption band was observed, and interpreted as being mainly caused by elastic collisions between excitons. The relationship between the photoinduced changes of the absorption and the exciton density was established. Radiative exciton - exciton interaction and surface recombination were revealed as the main recombination processes governing the decay of excitons in CuBr nanocrystals, and the relevant rate constants were evaluated.

https://iopscience.iop.org/article/10.1088/0953-8984/9/31/026/pdf

S. Pakalnis

Papers

Fast switching of the transmission of light by glasses activated with CdS microcrystals

Rapid processes of darkening and bleaching in CdS doped glasses

Dynamics of nonlinear optical response of CuBr-doped glasses

Transient effects in photoexcited CdS microcrystals

Dynamics of dense exciton gas in semiconductor nanocrystals