We have studied the emission properties of single CdTe/ZnTe quantum dots (QDs) grown on Si(001) substrates by using molecular beam epitaxy and atomic layer epitaxy. The good quality of the QDs is attested by the resolution-limited emission, negligible background and absence of measurable spectral jitter or blinking. Power-dependent, polarization-dependent, and temperature-dependent microphotoluminescence spectroscopy measurements were performed to identify the exciton, the biexciton, and two oppositely charged excitons in the emission spectra of single QDs.

A periodic nano-island array of ∼7 nm diameter Zn single crystals embedded in an amorphous Zn(2x)Si(1-x)O(2) layer was created by using rapid electron beam irradiation for 50 s. A sequential process of 900 °C thermal annealing followed by electron beam irradiation induces the formation of an amorphous Zn(2x)Si(1-x)O(2) layer containing periodic Zn nanocrystals. It is shown that the periodic Zn crystal array can be produced with good control of their size and spacing. Possible formation mechanisms for the Zn crystal nano-islands are described on the basis of the experimental results.

We synthesized nanocrystalline Y2O3:Eu phosphor by a novel sol-gel route using simple metal nitrates and alcohols as the starting materials instead of oxide powders and nitric acid. The structural characteristics and luminescence properties of the sol-gel derived nanocrystalline Y2O3:Eu phosphor were studied by X-ray diffraction, transmission electron microscopy, and photoluminescence measurement. The crystallized crystal size increased from 7 to 55 nm as the firing temperature was increased from 500 to 1000 o C. The red-emitting luminescence dominated by the 5 D0-7 F2 transition of the Eu 3+ ions. The intensity of the red luminescence increased with increasing firing temperature, and concentration quenching was observed with increasing Eu 3+ concentration.