The synthesis and characterization of some II-VI semiconductor quantum dots, quantum shells and quantum wells

The recent theoretical and practical interests in semiconductor nanomaterials results from the onset of quantum phenomena in the mesoscopic size range. The resulting size quantization effects occur, as the particle size becomes smaller than the exciton size. The confined exciton then exhibits discontinuous properties such as band gap enlargement and band discretization. The size reduction also leads to the confinement of phonons. Under stronger confinement the effects of exchange and correlation forces between to electron and hole contribute more. These quantum properties afford new and different applications of semiconductor nanostructures in contrast to bulk semiconductor materials. In particular, these confinement effects minimize exciton phonon interactions and enhance exchange-correlation effects. The effects together we thought to slow nonradiative relaxation of the exciton, increasing its stability. The room temperature exciton would allow many optoelectronic applications. The slower nonradiative relaxation in some materials and at interfaces may contribute to intraparticle charge separation and more efficient photovoltaic devices.