Cadmium selenide properties

RAFT polymerization lends itself to the synthesis of polymers with thiol end groups. Several groups have utilized the property of thiols and dilhioesLers to bind heavy metals such as gold or cadmium in preparing brushes based on gold film or nanoparticles1 8 761 763 and cadmium selenide nanoparticles.763 76 1... 

Let us add here that the fabrication of polycrystalline semiconductive films with enhanced photoresponse and increased resistance to electrochemical corrosion has been attempted by introducing semiconductor particles of colloidal dimensions to bulk deposited films, following the well-developed practice of producing composite metal and alloy deposits with improved thermal, mechanical, or anti-corrosion properties. Eor instance, it has been reported that colloidal cadmium sulfide [105] or mercuric sulfide [106] inclusions significanfly improve photoactivity and corrosion resistance of electrodeposited cadmium selenide. 

Surface effects on the properties of cadmium selenide quantum dots were investigated [90]. 

Pure cadmium selenide [1306-24-7], CdSe, is brownish black and has no pigment properties. Like cadmium sulfide, it is dimorphous and occurs in hexagonal and cubic modifications. Cadmium selenide is insoluble in dilute acid. It readily liberates hydrogen selenide in concentrated hydrochloric acid. It dissolves completely in fuming nitric acid, the Se2 - ions being converted to SeO2 ions. Cadmium selenide is an n-type semiconductor. 

Tenne R. and Hodes G. (1980), Improved efficiency of cadmium selenide photoanodes by photoelectrochemical etching , Appl. Phys. Lett. 37, 428-430. Tomkiewicz M., Ling 1., and Parsons W. S. (1982), Morphology, properties, and performance of electrodeposited normal CdSe in liquid-junction solar cells ,... 

PET/KOF] Petrova, Z. K., Kofrnan, N. A., Heat capacity and some thermodynamic properties of cadmium selenide, Dokl. Akad. Nauk BSSR, 20, (1976), 688-690, in Russian. Cited on pages 267, 268, 545. 

This section will consider in greater detail specific examples of particular types of nanomaterials interacting with different media in the environment. The fate and transport of carbon-based nanomaterials, including carbon nanotubes and fuUerenes, in aqueous environments and the properties of commercial oxide nanoparticles that affect their removal in water will be discussed. Nanomaterial exposure to soils and porous media, focusing on transport and retention, as well as environmental interactions of cadmium selenide (CdSe) quantum dots with biofilms will be presented. These specific examples provide an idea of the types of environmental interactions that must be considered, and illustrate that environmental impacts of nanomaterials cannot be generalized, but rather, are dependent on properties of the material in question and the environment to which it is exposed or transported. 

Semiconductor-Gas Interface. Photolumi-nescent Properties of Cadmium Selenide in the Presence of Amines, j. Am. Chem. Soc. 1988, 110,4914-4918. 

Nasar A, Shamsuddin M (1990) Thermodynamic properties of cadmium selenide. J Less-Common Met 158 131-135... 

Nanomaterials in the form of a colloidal solution or quantum dots are attributed to have a tremendous impact in analytical chemistry for their unique physical and chemical properties (Alivisatos 2004 Katz and Willner 2004). A different methodology has been adopted to analyse vitamin Bi spectro-fluorimetrically by using cadmium selenide quantum dots (CdSe QDs), cadmium telluride (CdTe) nanorods, and silica and gold nanoparticles. A fluorescence resonance Rayleigh scattering (RRS) method was applied for determining vitamin Bi at sub-nanomolar level (Liu et al. 2006). In this technique, vitamin Bi was mixed with acidic buffer and prepared gold nanoparticles. After incubation, the solution mixture was excited in synchronous mode to obtain RRS spectra. The RRS spectral intensity correlated with the concentration of vitamin Bi. 

Yellow cadmium sulfide is highly insoluble (more so than zinc sulfide) and can be predpitated from acidic solutions. Cadmium selenide is almost black and has no pigmentary properties, but is used in the semicondudor industry. 

Hands-on nanotechnology content materials based on semiconductor quantum dot nanociystals were developed for use in a broad range of educational settings including undergraduate major and non-major chemistry courses, an upper level undergraduate chemistry laboratory course and outreach activities for K-12 and general public audiences. The focus is the colorful trend exhibited by cadmium selenide (CdSe) and cadmium selenide sulfide (CdSCxSi.x) quantum dots, which is correlated with the physical size of nanosized quantum dots. This visual trend illustrates one of the central themes in nanoscience that physical properties often depend on size at the nanoscale. 

Our goal was to develop hands-on activities and laboratory experiments that could be adapted for delivery to the different constituent groups (2). Semiconductor quantum dots were chosen as the intellectual focus of the new instructional materials. More specifically, colloidal quantum dots, formed from cadmium selenide (CdSe) and cadmium selenide sulfide (CdSexSi.x) alloys were used to demonstrate the colorful trends that are correlated to the physical size of nanosized crystallites as shown in Figure 1. This visual trend vividly illustrates one of the central themes in nanoscience-/ /7y /ca/properties often depend on... 

Figure 2. Cadmium selenide (CdSe)quantum dot samples embedded in a polymer are used for outreach activities. The luminescent properties can he observed using the attached violet LED pen lights. The NANO IOWA logo on the cards reinforces the idea that the colors of the quantum dots depend on their size.

Properties of Cadmium Selenide Quantum Dots. 1. Phys. Chem., 97 (34)8727- 8731 28. 

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