Positron Annihilation Lifetime Measurements and Ab-initio Calculations on Al-doped ZnO Semiconductor Powders

L.C. DAMONTE; G.DARRIBA; M.RENTERÍA

Conferencia; International Conference on HYPERFINE Interactions and their Applications; 2016

Zinc oxide is a II-VI semiconductor with numerous technological applications such as optoelectronic devices, solar cells, gas sensors, etc. It is well known that the addition of different dopants, both as acceptors or donor, improve its performance. Powder mixtures of ZnO and Al2O3 in adequate proportion yielding different contents of Al (5, 10 and 30 at / vol %) were prepared by mechanical milling. The systems were characterized by XRD and positron lifetime measurements. The annihilation parameters evolution with milling time allows us to verify the dopant incorporation into the wurtzite structure or the formation of new phases. The equilibrium structures were obtained by the WIEN2k code which combined with MIKA program gives us the characteristic semiconductor lifetimes. Also, from ab-initio calculations the DOS was obtained as a function of the dopant concentration. Both, theoretical and experimental results are compared in order to get insight into the structural and electronic properties and their influence on devices performance.