NANOPARTICLES: SYNTHESIS, PROPERTIES & APPLICATIONS

In recent years, there has been an intense interest in the synthesis and characterization of nanoparticles. nanoparticles range in size from 1 to 100 nm in diameter. semiconductor nanoparticles from ~1 to ~20 nm in diameter are often called quantum dots, nanocrystals, or q-particles. in this size regime, the particles possess short-range structures that are essentially the same as the bulk semiconductors, yet have optical and/or electronic properties, which are dramatically different from the bulk. the confinement of electrons within a semiconductor nanocrystal results in the shift of the band gap to higher energy with smaller crystalline size. this effect is known as the “quantum size effect”. in the strong confinement regime, the actual size of the semiconductor particle determines the allowed energy levels and thus the optical and electronic properties of the material. due to their finite small size and the high surface-to-volume ratio, nanoparticles often exhibit novel, and sometimes-unique properties. the characterization of these properties can ultimately lead to identifying many potential uses and applications, ranging from catalysis, ceramics, microelectronics, sensors, pigments, magnetic storage to drug delivery and biomedical applications. research in this area is motivated by the possibility of designing nanostructured materials that possess novel electronic, optical, magnetic, mechanical, photochemical and catalytic properties. such materials are essential for technological advances in photonics, quantum electronics, nonlinear optics and information storage and processing.