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CO2 laser induced pyrolysis of silane was used to produce silicon nanoparticles with an average diameter as small as 5 nm at high rates (up to 200 mg/h). Etching these particles with a mixture of hydrofluoric acid (HF) and nitric acid (HNO3) reduces their size and passivates their surface such that they exhibit bright visible photoluminescence (PL). This(More)
The growth of silicon films via chemical vapor deposition (CVD) is of considerable importance in the microelectronics and photo-voltaics industries. This process often involves the thermal decomposition of silane, which is achieved by heating the wafer or rod to be coated to a suitable temperature. A wide range of geometries and conditions are employed. For(More)
Product contamination by particles nucleated within the processing environment often limits the deposition rate during chemical vapor deposition processes. A fundamental understanding of how these particles nucleate could allow higher growth rates while minimizing particle contamination. Here we present an extensive chemical kinetic mechanism for silicon(More)
Ž The structures and energies of eight fully saturated polycyclic polysilanes were investigated using ab initio molecular orbital calculations. Structures and vibrational 9 14 10 14 10 16 Ž. Ž. frequencies were computed at the HFr3-21G d level. A complete basis set extrapolation method CBS-4 was used to calculate the energies of the structures. Heats of(More)
Quantum dots have been used in biomedical research for imaging, diagnostics and sensing purposes. However, concerns over the cytotoxicity of their heavy metal constituents and conflicting results from in vitro and small animal toxicity studies have limited their translation towards clinical applications. Here, we show in a pilot study that rhesus macaques(More)
Current clinical therapies for critical-sized bone defects (CSBDs) remain far from ideal. Previous studies have demonstrated that engineering bone tissue using mesenchymal stem cells (MSCs) is feasible. However, this approach is not effective for CSBDs due to inadequate vascularization. In our previous study, we have developed an injectable and porous nano(More)
Tremendous research efforts have been devoted to fabricating high quality quantum dots (QDs) for applications in biology and medicine. Much of this research was pursued with an ultimate goal of using QDs in clinical applications. However, a great deal of concern has been voiced about the potential hazards of QDs due to their heavy-metal content. Many(More)
A method is presented for the preparation of a biocompatible ferrofluid containing dye-functionalized magnetite nanoparticles that can serve as fluorescent markers. This method entails the surface functionalization of magnetite nanoparticles using citric acid to produce a stable aqueous dispersion and the subsequent binding of fluorescent dyes to the(More)
Quantum dots (QDs) have size-dependent optical properties that make them uniquely advantageous for in vivo targeted fluorescence imaging, traceable delivery, and therapy. The use of group II-VI (e.g., CdSe) QDs for these applications is advancing rapidly. However, group II-VI QDs contain toxic heavy metals that limit their in vivo applications. Thus,(More)
Nanoparticles of iron have been prepared by laser-driven decomposition of iron pentacarbonyl vapor. In this method, an infrared laser rapidly heats a dilute mixture of precursor vapors to decompose the precursor and initiate particle nucleation. It was found that when using SF 6 as a photosensitizer during the synthesis, ferrous fluoride (FeF 2) was(More)