Structural and optical characteristics of ZnSe nanocrystals synthesized in the presence of a polymer capping agent

In this work, the electronic structures of quantum dots (QDs) of nine direct band gap semiconductor materials belonging to the group II-VI and III-V families are investigated, within the empirical tight-binding framework, in the effective bond orbital model. This methodology is shown to accurately describe these systems, yielding, at the same time, qualitative insights into their electronic properties. Various features of the bulk band structure such as band-gaps, band curvature, and band widths around symmetry points affect the quantum confinement of electrons and holes. These effects are identified and quantified. A comparison with experimental data yields good agreement with the calculations. These theoretical results would help quantify the optical response of QDs of these materials and provide useful input for applications.

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“…Other experimental data from the literature such as Leppert et al 80,81 and Chestnoy et al 82 compare rather well with our TB results.…”

Section: Znsesupporting

confidence: 91%

Electron states in semiconductor quantum dots

Dhayal

Ramaniah

Ruda

et al. 2014

The Journal of Chemical Physics

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“…Three concentrations of diethylzinc in heptane were used to obtain nanocrystal populations for photoluminescence experiments: 0.3, 0.03, and 0.003 M. The estimated particle size assuming 40 nm droplets is 8, 3.7, and 1.7 nm, respectively. The ZnSe bulk exciton Bohr diameter, below which confinement phenomena are expected, has been reported to be 9 nm . The PL emission spectra of the three representative particle populations obtained from the experiments are shown in Figure a.…”

Section: Resultsmentioning

confidence: 98%

Synthesis and Size Control of Luminescent ZnSe Nanocrystals by a Microemulsion−Gas Contacting Technique

et al. 2004

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A scalable method for controlled synthesis of luminescent compound semiconductor nanocrystals (quantum dots) using microemulsion-gas contacting at room temperature is reported. The technique exploits the dispersed phase of a microemulsion to form numerous identical nanoreactors. ZnSe quantum dots were synthesized by reacting hydrogen selenide gas with diethylzinc dissolved in the heptane nanodroplets of a microemulsion formed by self-assembly of a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) amphiphilic block copolymer in formamide. A single nanocrystal is grown in each nanodroplet, thus allowing good control of particle size by manipulation of the initial diethylzinc concentration in the heptane. The ZnSe nanocrystals exhibit size-dependent luminescence and excellent photostability.

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“…A limitation of these techniques is that the materials are usually nanoscale in only one dimension. Although sol−gel methods are also useful for creating three-dimensional nanoparticles, − the silicate glass matrix is subject to shrinking and cracking upon drying. Also, since the nanoparticles are permanently trapped within the matrix, they are difficult to remove for subsequent use in other media.…”

Section: Introductionmentioning

confidence: 99%