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A reverse cation-exchange approach is described for the synthesis of hollow PbSe nanospheres, which involves a step wise, in-situ template-based evolution from spherical amorphous Se colloids to Se/[Ag.sub.2]Se core/shell colloids, then to hollow PbSe nanospheres. The characterization results show that hollow PbSe nanospheres with polycrystalline and cubic structure are prepared and the conformation is beneficial to the improvement concerning the applications of PbSe nanostructures.

Size-controllable monodisperse PbSe and PbSe/PbS nanocrystals (NCs) are successfully synthesized with a solvothermal method. These narrow-band-gap semiconductor NCs with tunable size are expected to have potential applications in near- and mid-IR telecommunication laser sources, electroluminescence, and solar cell materials.

Conduction in thin films of PbSe nanocrystals doped by electrochemical gating was studied. Charging the film, with electrons or holes, increases the conductance by order of magnitude and the temperature and electric field dependence of conductance in the film measured between 4.3 and 135 K, were both well described by a variable range hopping model.

The single crystalline PbMoO4 dendrites were prepared by a simple hydrothermal method in the presence of surfactants. The formation and evolution of dendrites was investigated by transmission electron microscopy, and the results showed that the dendritic structure was achieved through oriented attachment of nanoparticles along crystallographically specific direction.

The phase instability's role in understanding the piezoelectricity in systems like Pb(Zr, Ti)[O.sub.3] is examined. The results have shown that the phase instability, in contrast with polarization rotation, is responsible for the large piezoelectric properties of systems like Pb(Zr, Ti)[O.sub.3] in the vicinity of the morphotropic phase boundary.

A new, simple, organometallic synthetic technique is described for the preparation of Cu, Pb, or both (co-)doped ZnS nanocrystals without injection of precursors. The technique can be further exploited for the synthesis of other doped, sulfide-based semiconductor materials.

Nanosized PbS is fabricated on the Ti[O.sub.2] films and the components of the modified Ti[O.sub.2] films are studied by X-ray diffraction (XRD) and electron probe microanalysis (EPMA). The results have shown that the surface modification with optimum nanosized PbS on Ti[O.sub.2] leads to a performance improvement effectively.

The surface structure of organically capped PbS nanocrystals using synchrotron radiation excited core-level photoelectron spectroscopy is studied. The results indicate that the trioctylphosphine ligands passivate only the surface S sites while oleic acid ligands appear to bind mainly to Pb sites.

The synthesis of new, efficient, visible light active photocatalysts through the incorporation of highly electronegative non-transition metal Pb or Sn ions into the perovskite lattice of Ba(In1/3M1/3M'1/3)O3 (M = Sn, Pb; M' = Nb, Ta) is discussed. A greater photocatalytic activity was observed in Pb-substituted derivatives under visible and ultraviolet-vis irradiations as compared to ternary Ba(In1/2M'1/2)O3 and quaternary Ba(In1/3Sn1/3M'1/3)O3 compounds (M' = Nb, Ta).

The electronic conductivity of PbS and CdTe nanoparticle monolayers was examined voltammetrically by using interdigitated array (IDA) electrodes at the air/water interface. The conductivity of the final interfinger deposits was about two orders of magnitude smaller than that for pure metallic lead, indicating some surface contamination and/or less than perfect crystalline structure.

Pb(super 2+) ion exchange in N-octadecanoyl-L-alanine Langmuir-Blodgett film is investigated by FTIR spectroscopy. The condensation effect of Pb (super 2+) gives rise to significant increase in the hydrogen-bonding interaction between adjacent molecules, so that a complete ion exchange occurs after Pb (super 2+) penetrates into the Langmuir-Blodgett film through structure defects.