We report on the influence of the chemical composition on the electronic properties of molybdenum oxynitrides thin films grown by reactive sputtering on Si (100) substrates at room temperature. The partial pressure of Ar was fixed at 90 %, and the remaining 10 % was adjusted with mixtures N2:O2 (varying from pure N2 to pure O2). The crystalline and electronic structures and the electrical transport of the films depend on the chemical composition. Thin films grown using oxygen mixtures up 2 % have gamma-Mo2N phase and display superconductivity. The superconducting critical temperature Tc reduces from ~ 6.8 K to below 3.0 K as the oxygen increases. On the other hand, films grown using oxygen mixtures richer than 2 % are mostly amorphous. The electrical transport shows a semiconductor-like behavior with variable-range hopping conduction at low temperatures. The analysis of the optical properties reveals that the samples have not a defined semiconductor band gap, which can be related to the high structural disorder and the excitation of electrons in a wide range of energies
@article{arxiv.1905.11909,
title = {Electrical conductivity in extremely disordered molybdenum oxynitrides thin films},
author = {J. A. Hofer and S. Bengio and G. Rozas and P. D. Pérez and M. Sirena and S. Suárez and N. Haberkorn},
journal= {arXiv preprint arXiv:1905.11909},
year = {2020}
}