Bikowski, A.; Rengachari, M.; Nie, M.; Wanderka, N.; Stender, P.; Schmitz, G.; Ellmer, K.:
Research Update: Inhomogeneous aluminium dopant distribution in magnetron sputtered ZnO:Al thin films and its influence on their electrical properties. APL Materials 3 (2015), p. 060701/1-12
10.1063/1.4922152
Open Accesn Version
Abstract:
The spatial distribution of Al in magnetron sputtered ZnO:Al films has been investigated
in depth. Two different kinds of inhomogeneities were observed: an enrichment
in the bulk of the film and an enrichment at the interface to the substrate. This has
been correlated to the electrical properties of the films: the former inhomogeneities
can lead to trap states at the grain boundaries limiting the free carrier mobility. The
latter can promote the formation of secondary phases, which leads to an electrical
inactivation of the dopant. Furthermore, this effect can contribute to the thickness
dependence of the electrical properties of ZnO:Al films.