Preparation of Small Silicon Carbide Quantum Dots by Wet Chemical Etching
- PDF / 20,887,388 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 49 Downloads / 213 Views
Preparation of Small Silicon Carbide Quantum Dots by Wet Chemical Etching D. Beke1,2, Zs. Szekrényes1, I. Balogh1, M. Veres1, É. Fazakas1, L. K. Varga1, Zs. Czigány3, K. Kamarás1, and A. Gali1,4 1 Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Konkoly-Thege M. út 29-33., H-1121 Budapest, Hungary 2 Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, Műegyetem rkp. 3., H-1111 Budapest, Hungary 3 Institute for Technical Physics and Materials Science, Research Centre of Natural Sciences, Hungarian Academy of Sciences, Konkoly-Thege M. út 29-33., H-1121 Budapest, Hungary 4 Department of Atomic Physics, Budapest University of Technology and Economics, Budafoki út 8., H-1111 Budapest, Hungary ABSTRACT Luminescence nanocrystals or quantum dots give grate potential for bio-analysis as well as optoelectronics. Here we report an effective and non-expensive fabrication method of silicon carbide nanocrystals, with diameter below 10 nm, based on electroless wet chemical etching. Our samples show strong violet-blue emission in the 410-450 nm region depending on the used solvents and particle size. Raman and infrared measurements suggest the varied nature of surfaces of silicon carbide nanocrystals which elucidate the behavior of the silicon carbide colloid solvents and also give opportunity to modify the surface easily for specific biological, medical or other application. INTRODUCTION Visual analysis of biomolecules is an integral avenue of basic and applied biological research. Quantum dots (QDs) are semiconductor inorganic nanoparticles that are emerging as alternative or complementary tools to the organic fluorescent dyes currently used in bioimaging. In comparison with traditional organic fluorophores, QDs have a number of advantages including broad excitation and narrow emission spectra. QDs are more resistant to photobleaching than their organic counterparts, making QDs as a superior alternative of bio-marker and further its applications in basic and applied biology [1]. QDs are often made from of group II and VI elements (e.g. CdSe and CdTe) [2] or group III and V elements (e.g. InP and InAs) [3]. Although these QDs have great potential as probes for bioimaging, certain limitations may restrict their applications. These QDs were found to be cytotoxic through the release of free metallic ions. Therefore, a protective shell must be systematically added. However, no protective shell can guarantee an efficient chemical isolation of the extremely toxic elements from the living cell environment. Cytotoxicity strongly influencing is one of the major limiting factors for the application of II-VI QDs in efficient in vivo imaging [4]. We propose silicon carbide nanocrystals (SiC NCs) for bioimaging in order to eliminate numerous disadvantages of traditional QDs. SiC is a stable, chemically inert wide band gap indirect semiconductor. SiC NCs, with about 3 eV excitation energy, were successfully fabricated in many ways [5-8
Data Loading...
