Modelling of density of states and energy level of chalcogenide quantum dots

Quantum dots (QDs) or semiconductor nanocrystals are luminous materials with unique optical properties that can be fine-tuned by varying the size of the material. Chalcogenide QDs show strong quantum confinements effects owing to the fact that the exciton Bohr radius is much larger than the particle size, and tunable energy bandgap leads to widespread technological interest in near-infrared optical devices. In this communication, one dimensional Cu2SnS3 and PbSexS1-x QDs is modeled by a particle in a box model which was used to compute energies and density of states. The density of states and the energy level of QDs are determined as a function of the strengths of the potential walls of the inner box. The results exhibit that the density of states decreases exponentially with an increase in the energy level of QDs. The density of states at lower energy levels is more significant than what is observed in higher energy levels.

An enzyme-like imprinted-polymer reactor with segregated quantum confinements for a tandem catalyst

This study was aimed at addressing the present challenge in tandem catalysts: how to furnish catalysts with tandem catalytic-ability without involving the precise control and man-made isolation of different types of catalytic sites.

Metal oxide rods and dots-based structures and devices: cost-effective fabrication and surface chemistry control

The necessity of materials development which is not limited to materials that can achieve their theoretical limits, but makes it possible to raise theoretical limits by changing the fundamental underlying physics and chemistry while keep the fabrication cost to a minimum is crucial. Materials nanotechnologies based on chemical fabrication approaches is one of the immediate answer to the enormous need for cost-effective new materials for energy, environment, and health. R&D exploiting chemical nanoscience and nanotechnology has the greatest potential to efficiently contribute to such challenging goals. Indeed, the creation of new materials with higher performance and improved stability achieved by atomic, molecular and nanostructural design and control using unique nanoscale phenomena such as quantum confinements is the key. A synthesis involving the aqueous condensation of metal ions from solutions of metal salts for the low-cost fabrication of engineered arrays consisting of oriented nanorods of metal oxides orientations onto various substrates as well as the ability to control the surface acidity of quantum dots from acidic to neutral to basic by size effect are presented.