Nanocrystals and Quantum Dots in Glasses
|
허종 포항공대 Semiconductors nanocrystals, in particular lead chalcogenide quantum dots (QDs) have been studied extensively as promising candidates for near-IR lasers, light emitting diodes (LED) and fiber-optic amplifiers because of their size dependent optical and electronic properties. It is particularly important to control the sizes of QDs precisely since their optical characteristics are critically dependent on the diameters of QDs precipitated. In addition to the conventional heat treatment technique, various methods were proposed for the efficient and precise control of the sizes of QDs. By optimizing the concentration of Nd3+ ions in glasses, wavelengths of the photoluminescence from PbS QDs were controlled to 1~2 m range that match the fiber-optic telecommunication window. Irradiation of the green laser assisted the formation of CdSe/Cd1-xZnxSe core/shell structure inside the glass that significantly decreased the adverse emission at λ=620 nm associated with the surface defects. This work reviews the several methods applied to control the size, shape and spatial distribution of quantum dots in inorganic glasses |