Zn-based semiconductor nanopowders doped by mechanical milling

L.G.VALLUZZI; M.G.VALLUZZI; M.MEYER; L.C. DAMONTE

Simposio; 25th International Symposium on Metastable, Amorphous and Nanostructured Materials (ISMANAM 2018); 2018

II-VI semiconductors are of interest due to their potential application as photovoltaicdevices like hybrid solar cells. The efficiency of these devices may be improvedmainly increasing charge carriers densities and interfacial processes. Inorder to reach this last purpose nanocrystalline materials are the best option assolar cells constituents. In this study we present zinc based semiconductors powderswhich optical and electrical properties have been modified by the Al presenceacting as small quantities of dopant.The nanosized doped semiconductors (ZnO, ZnSe and ZnTe) were obtained bymechanical milling which has been proved to be an effective and simple techniqueto produce nanocrystalline and large quantities of materials. The startingmaterials, the metal oxides (Al2O3) or the pure metal (Al) together with ZnO, ZnSeor ZnTe were milled in adequate proportion to obtain the desired concentration.Parameters such as initial concentrations, atmosphere and milling times were varied.Structural and optical characterization of doped powders by X-ray diffraction,Extended X-ray Absorption Spectroscopy (XAFS), scanning electron microscopy,positron lifetime measurements (PALS) and optical reflection spectroscopy weredone. Undoped ZnO, ZnSe and ZnTe nanocrystalline powders prepared in a similarway were analyze for comparison. The knowledge obtained can be of use togive direction to the improvement of the performance of hybrid organic/inorganicsolar cells.