Investigation of Nanostructures in Pb-O System by Solution and Vapor Growth Techniques

Metal-oxides and their nanostructures are today widely investigated because of their multiple functional properties and possible application in different fields. In this context, lead oxides remain a not completely explored case and their nanostructures are not frequently reported in literature. Lead and oxygen forms several compounds, differing in stoichiometric ratio and crystalline structures. This aspect makes the study of these oxides even more complicate. Aim of this work is the investigation of synthesis approaches to the growth of lead oxide nanostructures, and in particular of lead monoxide (PbO), which is a promising high-Z material for radiation detection. In particular the availability of single-crystal nanostructures could allow better investigations of transport properties, which is a fundamental parameter for detectors realization but not well defined for this material. Both solution and vapor based synthesis methods have been explored in order to obtain nanostructures with the desired crystalline structures. Different wet reactions starting from lead salt precursors have been tested as a function of the synthesis parameters (pH, temperature, concentration,...). Vapor phase growth has been instead based on the thermal evaporation and controlled oxidation of metallic lead, in order to promote the formation of the oxides with the lowest oxidation state. Structural and optical properties of the obtained nanostructures have been characterized and the different results have been compared.