We have synthesized high quality type-II CdTe/CdSe near infrared quantum dots using successive ion layer adsorption and reaction chemistry. Transmission electron microscopy reveals that CdTe/CdSe can be synthesized layer by layer yielding quantum dots of narrow size distribution. Excitation and photoluminescence spectra reveal discrete type-II transitions, which correspond to energy lower that ...

Investigation into integrated PEC/PVC for water splitting and light harvesting has focused on doping, QD sensitization and nanomaterials morphology. We have demonstrated, for the first time, PVC based on combined use of nitrogen doping and CdSe QD sensitization of nanocrystalline TiO2 thin films with promising results for solar energy conversion. Such TiO2:N/CdSe PVC produced an incident-photon...

We have demonstrated that seeded growth of nanocrystals offers a convenient way to design nanoheterostructures with complex shapes and morphologies by changing the crystalline structure of the seed. By using CdSe nanocrystals with wurtzite and zinc blende structure as seeds for growth of CdS nanorods, we synthesized CdSe/CdS heterostructure nanorods and nanotetrapods, respectively. Both of thes...

Dendritic Ag2Se nanostructures are synthesized in a dry environment by UV irradiating the hybrids composed of CdSe quantum dots (QDs) and silver (Ag). UV irradiation on CdSe QDs induces a photooxidation effect on the QD surface and leads to the formation of SeO2 components. Then SeO2 reacts with the Ag atoms in either Ag film or QD layer to produce the Ag2Se. The growth mechanism of Ag2Se dendr...

First-principles density functional theory (DFT) simulations were carried out to study the strain dependence on the electronic and optical properties of cadmium selenide (CdSe) nanowires (NWs). The band structures, effective masses of electron and holes, dielectric properties, and other optical properties (such as extinction coefficient, optical reflectivity, and absorption coefficient) were ca...

The electronic surface states and dielectric self-energy profiles in CdSe colloidal nanoscale platelets are explored by means of an original ab initio approach. In particular, we show how the different coatings deeply modify the quantum and dielectric confinement in CdSe nanoscale platelets. Molecular coating leads to an electronic band gap free of electronic surface states as well as an optima...

ZnO/Zn x Cd1-x Se coaxial nanowires (NWs) have been successfully synthesized by combining chemical vapor deposition with a facile alternant physical deposition method. The shell composition x can be precisely tuned in the whole region (0 ≤ x ≤ 1) by adjusting growth time ratio of ZnSe to CdSe. As a result, the effective bandgaps of coaxial nanowires were conveniently modified from 1.85 eV to 2....

Ultra-thin quantum wells of CdTe and CdSe and fractional monolayer quantum dots of CdSe present very strong excitonic emission covering the red-blue spectral range. They are grown by atomic layer epitaxy and the thickness fluctuations can be completely avoided in many cases by choosing the appropriate substrate temperature. These systems appear as promising candidates for the elaboration of red...

We report evidence that paramagnetism in CdSe QDs can be induced via manipulation of the surface chemistry. Using SQUID magnetometry and X-ray absorption spectroscopy, we demonstrate that the paramagnetic behavior of the CdSe QDs can be varied by changing the ligand end-group functionality of the passivating layer. Contrary to previous reports, no evidence for ferromagnetism was observed. The r...