We report on the zinc oxide (ZnO) thin films obtained by the atomic layer deposition (ALD) method using diethyl zinc and water precursors, which allowed us to lower deposition temperature to below 200 °C. The so-obtained “as grown” ZnO layers are polycrystalline and show excitonic photoluminescence (PL) at room temperature, even if the deposition temperature was lowered down to 100 °C. Defect-related PL bands are of low intensity and are absent for layers grown at 140−200 °C. This is evidence that extremely low temperature growth by ALD can result in high quality ZnO thin films with inefficient nonradiative decay channels and with thermodynamically blocked self-compensation processes.

We report on the electrical properties of thin film transistors based on zinc oxide (ZnO) layers grown by low temperature (100–170°C) atomic layer deposition. As evidenced through Hall effect measurements, a drastic decrease of the carrier concentration occurred for ZnO films grown at 100°C. Time of flight–secondary ions mass spectroscopy analysis revealed that this decrease is associated with an increase of the hydroxide groups in the ZnO layer which suppressed oxygen vacancy formation. Transistors fabricated from ZnO films grown at 100°C exhibit a high Ion∕Ioff ratio (∼107) and an encouraging intrinsic channel mobility (∼1cm2∕Vs).

Epitaxial thin films of LaNiO 3−x were deposited by using a reactive d.c. magnetron sputtering technique. High-energy X-ray photoelectron spectroscopy was used to analyze the composition and valence states of La and Ni in the films after long time aging in atmosphere. The obtained results show the existence lanthanum and nickel in oxide and hydroxide chemical states. The oxygen exists in four chemical states: lattice oxides, hydroxyl groups and in adsorbed water. Comparison of the spectra recorded at normal emission and grazing emission angle revealed that the hydroxyl group's concentration is mostly present at the surface of the film.

Katsia, E.; Huby, N.; Tallarida, G.; Kutrzeba-Kotowska, B.; Perego, M.; Ferrari, S.; Krebs, Frederik C; Guziewicz, E.; Godlewski, M.; Osinniy, V.; Luka, G.