objective(s):  the field of nanotechnology is rapidly expanding .the development quantum dots quantum dot (qds), show great promise for treatment and diagnosis of cancer and targeted drug delivery little data on the toxicity of qds, especially for in vivo applications, are available. as a result, concerns exist over their toxicity for in vivo applications. then, cytotoxic effects of cadmium sel...

This study examines the dynamics of personality traits that interfere with occupational decisions among young adults, especially during a pandemic. Three multiple regression analyses were conducted to predict career decision self-efficacy (CDSE), e.g., planning and indecision from Big 5 measures. We hypothesized EI affect employment conflicts (Study 1), CDSE mediates difficulty 2). Conscientiou...

Stable water soluble surfactant coated CdSe nanocrystals with trioctylphosphine (TOP) were obtained by a process of dynamic surface coating with cationic, anionic, and non-ionic surfactants. The surfactant-coated CdSe/TOP nanocrystals were characterized by complementary techniques of UV-VIS and photo-luminescence spectrophotometry, as well as by means of a capillary zone electrophoretic techniq...

CdSe/ZnSe quantum structures grown on GaAs~001! by molecular-beam epitaxy were systematically investigated by high-resolution x-ray diffraction and high-resolution transmission-electron microscopy. Half of the initial Cd deposit redesorbs when migration-enhanced epitaxy is used instead of conventional molecular-beam epitaxy for the overgrowth of the CdSe by ZnSe. This result is explained by a s...

Composite photocatalysts are crucial for photocatalytic hydrogen evolution. In this work, ZrO2/CdSe-diethylenetriamine (ZrO2/CdSe-DETA) heterojunction nanocomposites synthesized, and efficiently stably catalyzed evolution under visible light. X-ray photoelectron spectroscopy (XPS) high resolution transmission electron microscope (HRTEM) confirm the formation of heterojunctions between ZrO2 (ZO)...

The evolution of CdSe quantum dot (QD) formation on ZnSe was investigated on a series of samples grown by MBE, with nominal CdSe coverages ranging from 1.1 to 2.6 monolayers (ML). Micro-PL data suggest strongly con"ned zero-dimensional excitons even for coverages as low as 1.1 ML. PL and micro-PL data show emission from the QDs as well as from an accompanying 2 D layer; the temperature dependen...

In this paper, CdSe nanocrystal dissolution in an aqueous solution was studied. It was found that light is a key factor affecting the dissolution of nanocrystals. In the presence of light, the electrons generated from CdSe nanocrystals reduce water to hydrogen and hydroxide ions (OH-) while photo-generated holes oxidize CdSe to Cd2+ and elemental Se. The dissolution was accelerated in an acidic...

We report a synthesis of highly luminescent (CdSe)ZnS composite quantum dots with CdSe cores ranging in diameter from 23 to 55 Å. The narrow photoluminescence (fwhm e 40 nm) from these composite dots spans most of the visible spectrum from blue through red with quantum yields of 30-50% at room temperature. We characterize these materials using a range of optical and structural techniques. Optic...

A key consideration for the efficient operation of hybrid solar cells based upon conjugated polymers and inorganic semiconductor nanocrystals is charge transport in the nanocrystal phase. Here we report the results of a study into the charge transport kinetics of polymer/nanocrystal solar cells based on blends poly(3-hexylthiophene) (P3HT) with either CdSe nano-dots or CdSe nano-tetrapods. Tran...

Fluorescent semiconductor nanoparticles, or quantum dots, have potential uses as an optical material, in which the optoelectronic properties can be tuned precisely by particle size. Advances in chemical synthesis have led to improvements in size and shape control, cost, and safety. A limiting step in large-scale production is identified to be the raw materials cost, in which a common synthesis ...