Structural and Optical Characterization of Mechanical Milled Doped Zn-Based Semiconductors Powders

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

Simposio; ISMANAM 2017; 2017

II-VI semiconductors are of interest due to their potential application as photovoltaic devices like hybrid solar cells. The efficiency of these devices may be improved mainly increasing charge carriers densities and interfacial processes. In order to reach this last goal nanocrystalline materials are the best option as solar cells constituents. In this study we present zinc based semiconductors powders which structural and optical properties have been modified by the Al presence acting as small quantities of dopant. The nanosized doped semiconductors (ZnSe and ZnTe) were obtained by mechanical milling which has been proved to be an effective and simple technique to produce nanocrystalline and large quantities of materials. The starting materials, the metal oxides (Al2O3) together with ZnSe or 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) and optical reflection spectroscopy were done. Undoped ZnSe and ZnTe nanocrystalline powders prepared in a similar way were analyze for comparison. XAFS spectra were analyzed using the IFFEFIT software, with the Athena and Arthemis implementation. The results suggested that Al atoms are incorporated in substitutional Zn sites into the ZnSe and ZnTe structures (Figure 1).The knowledge obtained can be of use to give direction to the improvement of the performance of hybrid organic/inorganic solar cells.