Semiconductor quantum dots Subject

Certain chromophore systems are intrinsically predisposed for ultrafast single molecule microscopy. Among these, emitters coupled to metal surfaces stand out as exceptionally well-suited subjects. Numerous observations of substantial radiative rate enhancement at the surface or in the vicinity of the surface of a metal were reported. Radiative rate enhancements as large as 10 have been predicted for molecular fluorophores and for semiconductor quantum dots coupled to optimized nanoantennae.Such accelerated emission rates put these systems well within the reach of the emerging femtosecond microscopy techniques. As a result, we decided to apply the Kerr-gated microscope to study of fluorescence dynamics of individual core-shell quantum dots in contact with smooth and nanostructured metal surfaces. 

The modification of photoluminescence (PL) from atoms and molecules located near metal nanostructured surfaces and nanobodies is an interesting subject in nanoscience. Its study gives new insights into the basic aspects of field-matter interaction [1,2], Semiconductor nanocrystals (quantum dots, QDs) possess a number of advantageous features as light emitters [3] and fluorescent labels [4] as compared to ionic and molecular chromophores. 

Quantum dots (QDs) are nanosized semiconductor particles of group II-VI or III-V main group elements with diameters of less than 10 nm [123]. These were first characterized in 1983 by Brus [124] as small semiconductor spheres in a colloidal suspension. QDs due to their nanoscale dimensions are subject to strong quantum confinement, which results in unique optical properties. Thus, in the last two decades, synthesis of QDs has attracted a lot of attention and generated a large number of publications [125]. A variety of methods have been proposed and implemented for synthesis of QDs. Of these methods, colloidal synthesis is the most accessible method for producing QDs suspended in solution. Colloidal synthesis of CdSe QDs is shown in Fig. 4. A cadmium compound is heated to 320°C... 

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