We demonstrate a low cost, phosphine-free route to synthesize CdSe quantum dots (QDs) by heating the mixed precursors of Se and Cd up to 260 C. The as-synthesized CdSe QDs are characterized by using UV-visible absorption spectroscopy, high resolution transmission electron microscopy, X-ray diffractrometry, and EDX analyses. The CdSe QDsensitized TiO2 films of solar cells has been fabricated by ...

The two-dimensional heterostructure nanobelts with a central CdSe region and lateral CdS structures are synthesized by a two-step physical vapor transport method. The large growth rate difference between lateral CdS structures on both +/- (0001) sides of the CdSe region is found. The growth anisotropy is discussed in terms of the polar nature of the side +/- (0001) surfaces of CdSe. High-resolu...

We developed a novel one-pot polyol approach for the synthesis of biocompatible CdSe quantum dots (QDs) using poly(acrylic acid) (PAA) as a capping ligand at 240°C. The morphological and structural characterization confirmed the formation of biocompatible and monodisperse CdSe QDs with several nanometers in size. The encapsulation of CdS thin layers on the surface of CdSe QDs (CdSe/CdS core-she...

The structure evolution of CdSe nanocrystal with different grown sizes (1.9, 2.7 and 3.1 nm, respectively) obtained by size-selective method from colloidal solution is investigated by XAFS. By such purposeful design of samples, we have investigated the isolated ripening process effect on the structure of nanocrystals. The Se K-edge XAFS results of CdSe nanocrystals show that structure disorder ...

With their bright, photostable fluorescence, semiconductor quantum dots show promise as alternatives to organic dyes for biological labeling. Questions about their potential cytotoxicity, however, remain unanswered. While cytotoxicity of bulk cadmium selenide (CdSe) is well documented, a number of groups have suggested that CdSe QDs are cytocompatible, at least with some immortalized cell lines...

CdSe nanospheres and dendrites have been successfully synthesized via an ionic liquid-assisted hydrothermal synthetic method. The samples are characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). Our experimental results demonstrate that the CdSe dendrites are obt...

Time Resolved Photoluminescence (TRPL) measurements on the picosecond time scale (temporal resolution of 17 ps) on colloidal CdSe and CdSe/ZnS Quantum Dots (QDs) were performed. Transient PL spectra reveal three emission peaks with different lifetimes (60 ps, 460 ps and 9–10 ns, from the bluest to the reddest peak). By considering the characteristic decay times and by comparing the energetic se...

We have successfully fabricated single-crystalline CdSe nanowires, nanobelts, and sheets by a chemical vapor deposition (CVD) method assisted with laser ablation. The synthesized CdSe nanostructures have hexagonal wurtzite phase as characterized by X-ray diffraction (XRD). CdSe nanobelts can range in length from several tens to a hundred micrometers, in thickness from 40 to 70 nm, and a tapered...

We report on the fabrication of CdSe quantum dot (QD) sensitized electrodes by direct adsorption of colloidal QDs on mesoporous TiO2 followed by 3-mercaptopropionic acid (MPA) ligand exchange. High efficiency photoelectrochemical hydrogen generation is demonstrated by means of these electrodes. The deposition of ZnS on TiO2/CdSe further improves the external quantum efficiency from 63% to 85% a...

CdSe/CdS/ZnS core-shell-shell quantum dots (QDs) were synthesized by using a solution process. High-resolution transmission electron microscopy images and energy dispersive spectroscopy profiles confirmed that stoichiometric CdSe/CdS/ZnS core-shell-shell QDs were formed. Ultraviolet-visible absorption and photoluminescence (PL) spectra of CdSe/CdS/ZnS core-shell-shell QDs showed the dominant ex...