Anisotropic chemical etching of semipolar [1011]/[101+1] ZnO crystallographic planes: polarity versus dangling bonds.
ZnO thin films grown by metal-organic vapor phase epitaxy along the nonpolar [formula: see text] direction and exhibiting semipolar [formula: see text] facets have been chemically etched with HCl. In order to get an insight into the influence of the ZnO wurtzite structure in the chemical reactivity of the material, Kelvin probe microscopy and convergent beam electron diffraction have been employed to unambiguously determine the absolute polarity of the facets, showing that [formula: see text] facets are unstable upon etching in an HCl solution and transform into [formula: see text] planes. In contrast, [formula: see text] facets undergo homogeneous chemical etching perpendicular to the initial crystallographic plane. The observed etching behavior has been explained in terms of surface oxygen dangling bond density, suggesting that the macroscopic polarity plays a secondary role in the etching process.
Departamento de Física, Edificio CIOyN (Campus Espinardo), Universidad de Murcia, E-30100 Murcia, Spain.
E
E
Palacios-Lidón
B
B
Pérez-García
P
P
Vennéguès
J
J
Colchero
V
V
Muñoz-Sanjosé
J
J
Zúñiga-Pérez