PALS AND AB INITIO/DFT CALCULATIONS ON ZN-BASED NANOSTRUCTURED SEMICONDUCTORS

DARRIBA, G.N.; MARCOS MEYER; M.RENTERÍA; L.C. DAMONTE

Conferencia; International conference on HYPERFINE interactions and their applications; 2021

Positron Annihilation Lifetime Spectroscopy (PALS) and first-principles calculations werecombine to characterize structural and electronic properties on Zn-based II-VIsemiconductors. ZnT (T:O, Se and Te) pure and Al doped nanopowders were obtained bymechanical milling at increasing milling times. The progressive substitutional incorporationof Al atoms into the Zn-based semiconductor structure could be monitoring by PALSmeasurements identifying, also the defects induced by mechanical work. Additionally,combining two first-principles methods based on the Density Functional Theory (DFT) wecalculated the final equilibrium structures for different concentrations of Al doping and Znvacancies in these nanopowder semiconductors, predicting afterwards the characteristicpositron annihilation lifetimes at these equilibrium structures. This experimental and abinitio/DFT combined study allows us to verify the dopant incorporation into the Zn basedpure crystalline structures and to characterize the mechanical induced defects. Finally, withthe aim to elucidate electronic distortions introduced by the different defects (Alsubstitutional, Zn vacancies) in the semiconductors the electronic density of states (DOS)were evaluated confirming the semiconductor character of all samples. The jointexperimental and theoretical analysis will allow us to a better comprehension on thestructural and optical properties of these semiconductors towards their potential applications.