PERSONAL DE APOYO
VALDEZ Lucy Alejandra
congresos y reuniones científicas
Título:
Strain effects on the elastic and electronic properties of core/shell nanowires of ZnO/ZnX (X= ZnS, BeO)
Autor/es:
VALDEZ, LUCY ALEJANDRA; CASALI, RICARDO ANTONIO; CARAVACA, MARIA DE LOS ANGELES
Lugar:
Londres
Reunión:
Conferencia; 23 International Conference of Nanomaterials and Nanotechnology; 2018
Resumen:
ZnO is an important semiconductor due to its wide range oftechnological applications, which are based on their propertieslike as direct band gap, high conductivity and piezoelectricity.Some of them are improved at the nanoscale. In the last years,ZnO/X (X=ZnS, BeO) nanowires have demonstrated anupgrade in piezoelectronic sensons, photovoltaic cells andoptoelectronic devices than nanowires based on a singularZnO. However, the elastic properties have been scarcelyexplored. For that reason, we present an ab initio study aboutproperties such as Young Modulus, Poisson ratio, band gap andformation energy relative to nanowires sizes diameters. In orderto contribute in the design criteria, we have studied the effectson the elastic and electronic properties of uniaxial strain alongthe [0001] direction on hexagonal cross-sectional nanowireswhose diameters range from 1.0 to 2.88 nm. We found animproved in elastic properties with respect to ZnO single crystal.For the case of ZnO/shell nanowires, if the ZnS layers areadded the Young modulus, Poisson ratio and gap energydecrease, but if the BeO layers are added, the Young andPoisson ratio decrease while the band gap increase. Respect tothe maximum strain, we found is very sensitive to the shell type.Therefore, we could modulate the elastic properties and modifythe toughness according to the shell chemical elements andtheir wide. Apart from this, the calculated effective mass wasfound larger in nanowires than ZnO single crystal. The additionof ZnS layers increase the surface energy compared with BeOlayers of the same sizes. By means of the density of states, wecan show the contribution of the surface atoms to states near tothe Fermi level and distinguished by the shell type.