Al-Doped-ZnO mechanical milled nano-sized powders for dye sensitized cells

LAURA CRISTINA DAMONTE; V. DONDERIS; SERGIO FERRARI; J. OROZCO; M. A. HERNADEZ-FENALLOSA

Estrasburgo

Encuentro; E-MRS Spring 2009 Meeting; 2009

European Material Research Society

A growing interest in the development of cheap hybrid organic/inorganic photovoltaic cells consisting of a wide band gap semiconductor and conjugated polymer as sensitize has been arise in the last years. In this study we present zinc oxide nanoparticles which optical and electrical properties have been modified by the Al presence acting as small quantities of dopant. The aim of this study is to improve the compatibility of both compounds present in the bulk heterojunction in blend films based photovoltaic solar cells. The nano sized (around 20nm) powder of zinc oxide compounds were prepared by mechanically milling which has been proved to be an effective and simple technique to produce nanocrystalline powders and the possibility of obtain large quantities of materials. In a previous work [1], we have successfully obtained the ternary Zn1-xAlxO oxide using Al metal and ZnO as starting materials. Al is a trivalent dopant in the Zn lattice so it will be interesting to use its oxide as precursor and compare the obtained final product for both cases. Parameters such as initial concentrations, atmosphere and milling times were varied. Structural and optical characterization of ZnO-doped powders by X-ray diffraction, positron annihilation spectroscopy, scanning electron microscopy and optical reflection spectroscopy were done. Undoped ZnO nanocrystalline powders prepared in a similar way were analyze for comparison. The knowledge obtained can be of use to give direction to the improvement of the performance of hybrid organic/inorganic solar cells