Options
2017
Journal Article
Titel
Structural and electron transport properties of single-crystalline In2o3 films compensated by Ni acceptors
Abstract
For device applications, the ability to grow semi-insulating or p-type indium oxide (In2O3) is highly desirable. With this in focus, high quality single-crystalline Ni-doped In2O3 films have been grown by plasma-assisted molecular beam epitaxy and structurally and electrically characterized. Within a concentration range of approximately 1017-1019 cm−3, Ni is fully incorporated in the In2O3 lattice without the formation of secondary phases. At doping higher than roughly 1020 cm−3, secondary phases seem to start forming. No film exhibits p-type conductivity at room temperature. Instead, Ni is shown to be a deep compensating acceptor-confirming theoretical calculations, the effect of which only becomes apparent after annealing in oxygen. Combined Hall and Seebeck measurements reveal the compensation of bulk donors already at low Ni concentrations (∼1018 cm−3) and a residual film conductance due to mainly the interface region to the substrate. This residual conductance is gradually pinched off with increasing Ni doping, eventually resulting in semi-insulating films at excessive Ni concentrations (∼1021 cm−3).
Author(s)