Creation of Acceptor Centers in ZnO Single Crystals by Annealing in Sb Vapor

Abstract

We have investigated the influence of Sb on the carrier concentration of ZnO single crystals. ZnO single crystal substrates were doped in a sealed ampule by annealing in the Sb vapor at temperatures from 700 to 900 °C to create acceptor centers in ZnO. The dopant concentration profiles were determined by secondary ion mass spectrometry. A significant distinction in dopant concentrations as well as depth of penetration was observed for different temperatures of annealing. Electrical properties of the samples were studied by the Hall Effect and resistivity measurements. Valence states of Sb in the samples were investigated by the X-ray photoelectron spectroscopy method to prove the incorporation of the latter in the matrix of ZnO before and after oxygen annealing. The evolution of the carrier concentration of ZnO along with the valence state of Sb is explained.

Doping Nature of Group V Elements in ZnO Single Crystals Grown from Melts at High Pressure

“…In the previous study, we showed that doping of ZnO single crystals by Sb from the vapor in the absence of an external oxidant results in the ZnO structure containing exclusively Sb 5+ when only surface layers are studied. One would assume that a different situation might hold for the bulk of doped ZnO.…”

“…Moreover, accessibility of the dopant source might be an additional challenge. Instead of growing doped ZnO single crystals, there were attempts of introducing P and Sb via annealing of prepared single crystals in the vapor. An alternative approach of introducing dopants by ion implantation was realized for As .…”

Colloidal Approaches to Zinc Oxide Nanocrystals

“…This was the first report of a group IV aliovalent dopant in colloidal ZnO and provides a platform to study other potential two electron donors. Other nonconventional aliovalent dopants include Sb, which has been reported to adopt both 3+ and 5+ oxidation states in bulk ZnO . A single report of colloidal Sb-doped ZnO NCs appeared in 2019 by Baek et al where all of the Sb 3+ precursors was detected as Sb 5+ in the resulting ZnO NCs by X-ray photoelectron spectroscopy (XPS) .…”

“…Other nonconventional aliovalent dopants include Sb, which has been reported to adopt both 3+ and 5+ oxidation states in bulk ZnO. 258 A single report of colloidal Sb-doped ZnO NCs appeared in 2019 by Baek et al where all of the Sb 3+ precursors was detected as Sb 5+ in the resulting ZnO NCs by X-ray photoelectron spectroscopy (XPS). 259 The authors attribute the stabilization of Sb 5+ in the ZnO lattice to substitution of Sb at a Zn site, with two additional Zn vacancies (V Zn ) nearby forming an anionic [Sb Zn −2V Zn ] − complex, which is predicted to be a ptype defect.…”