Radial-Position-Controlled Doping in CdS/ZnS Core/Shell Nanocrystals

Abstract

In this paper, we report a new doping approach using a three-step synthesis to make high-quality Mn-doped CdS/ZnS core/shell nanocrystals. This approach allows precise control of the Mn radial position and doping level in the core/shell nanocrystals. On the basis of this synthetic advance, we have demonstrated the first example in which optical properties of Mn-doped nanocrystals strongly depend on Mn radial positions inside the nanocrystals. In addition, we have synthesized nanocrystals with a room-temperature Mn-emission quantum yield of 56%, which is nearly twice as high as that of the best Mn-doped nanocrystals reported previously. Nanocrystals with such a high-emission quantum yield are very important to applications such as nanocrystal-based biomedical diagnosis.

Tuninggfactors of core-shell nanoparticles by controlled positioning of magnetic impurities

“…It was therefore anticipated that precise control of magnetic impurity doping in coreshell nanoparticles and other nanoscale heterostructures could lead to new functionalities. [15][16][17][18][19][20][21] Chemists now have the ability to selectively dope core-shell nanoparticles with magnetic impurities at a specific and precisely defined radius. 20,[22][23][24] For instance, radial positioncontrolled Mn doping of zinc-blende CdS-ZnS core-shell nanoparticles was achieved using a three-step process which includes CdS-core growth, Mn-dopant growth in a thin spherical doping layer (inside either core or shell), and ZnS-shell growth.…”

“…[15][16][17][18][19][20][21] Chemists now have the ability to selectively dope core-shell nanoparticles with magnetic impurities at a specific and precisely defined radius. 20,[22][23][24] For instance, radial positioncontrolled Mn doping of zinc-blende CdS-ZnS core-shell nanoparticles was achieved using a three-step process which includes CdS-core growth, Mn-dopant growth in a thin spherical doping layer (inside either core or shell), and ZnS-shell growth. 20,[22][23][24] As a result, the optical properties of these nanoparticles can be tuned by varying the core and shell thicknesses and the spintronic properties can be tailored by precise positioning of the magnetic impurities.…”

“…20,[22][23][24] For instance, radial positioncontrolled Mn doping of zinc-blende CdS-ZnS core-shell nanoparticles was achieved using a three-step process which includes CdS-core growth, Mn-dopant growth in a thin spherical doping layer (inside either core or shell), and ZnS-shell growth. 20,[22][23][24] As a result, the optical properties of these nanoparticles can be tuned by varying the core and shell thicknesses and the spintronic properties can be tailored by precise positioning of the magnetic impurities. In addition to providing for control of carrier concentration and spin, dopants themselves can also serve as sensitive radial pressure gauges for measuring lattice strains due to lattice mismatch at the coreshell interface.…”

Synthesis of TiO2/SnO2 core shell nanocomposite via sol-gel method

“…The core and shell may be composed of a variety of materials including polymers, inorganic solids, and metals. [2][3][4][5] core shell particles have diverse applications in coatings, impact modification, bio-separation, drug delivery systems, etc. 6 The synthesis core shell particles typically involves tailoring the surface properties of particles, often accomplished by coating or encapsulating them within a shell of a preferred material.…”

First-principles calculations of lattice-strained core-shell nanocrystals

“…By varying the chemistry and thickness of each region, one can tune these nanocrystals to possess a wide range of properties, leading to applications in diverse areas such as optoelectronics, 1 biolabelling and sensing, 2 light emitting diodes, 3 solar cells, 4 photovoltaic materials, 5 spintronics, 6,7 and lasers 8 using different growth techniques. [9][10][11][12][13] .…”