Dopants incorporation in ZnO mechanical milled powders sensed by positrons

Abstract

M-doped ZnO (M: Cd, Mg) powders obtained by mechanical milling were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and positron lifetime annihilation spectroscopy (PALS). The mixing of the oxides is followed by means of XRD and SEM. As milling proceeds, a clear reduction of grain size and homogenization are observed. The evolution of annihilation parameters with milling time and cation content were analyzed and related with the kind of mechanical induced defect involved. Ternary oxides Zn 1−x M x O were efficiency obtained for certain compositions. The results showed that positrons constitute a well suited probe to characterize the cation substitution in the ZnO oxide lattice.

Al-doped ZnO mechanical milled powders for dye sensitized cells

“…After 16 h of milling annihilation lifetime parameters for Al 2 O 3 -doped ZnO sample reach almost those parameters yielded for milled pure ZnO powder. Similar trends and in consequence similar statements were previously arises for other dopants as Mg, Cd and Al [19,22].…”

“…3 together with resulting values for pure ZnO powder. Previous results [22] on mixture of metallic Al powder with ZnO and other dopants [19] are also included for comparison. For the present case, it can be seen that ave has a similar value to the one corresponding to other oxides mixtures already reported.…”

“…In this study we present zinc oxide nanoparticles which optical and electrical properties have been modified by the Al 2 O 3 presence acting as small quantities of dopant using mechanical milling. Milling has been proved to be an effective and simple technique to produce nanocrystalline powders with the possibility of obtain large quantities of materials [17,18] and also as a method of doping [19]. 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 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 phases formation depends on the initial conditions and enthalpy of phase's formation [17][18][19][20]. Fe-doped semiconductors were recently prepared by mechanical milling starting from oxides and pure metal powders.…”