Atomic layer deposition of nitrogen incorporated molybdenum oxide: Unveiling carrier transport mechanism and its application in Li-ion battery

Abstract

Nitrogen incorporated molybdenum oxide (MoOx:N) thin films are obtained by stacking of atomic layer deposited grown MoOx and MoNx in a nanolaminate architecture without any postdeposition processing. Evolution of stoichiometrically dependent electron conductivity is obtained that is efficiently controlled by varying the ratio of the number of layers (MoOx to MoNx) in the nanolaminate structure. The carrier type, the free carrier concentration, and the mobility of the as-grown materials are studied by temperature-dependent Hall-effect measurement. The authors hypothesize that the addition of N-atom creates oxygen vacancies in the films that in turn act as a shallow donor level that results in improved conductivity in the ternary material. As-grown materials, both in the form of planar architecture and coaxially grown on multiwalled carbon nanotubes are investigated as a prospective anode material in the Li-ion battery. The comparison reveals a substantially improved performance of N-incorporated samples than that of the pristine materials. The highest discharge capacity of 1287 mA h g−1 was achieved in the first cycle at a current rate of 0.1 A g−1, and a stable capacity of 974 and 610 mA h g−1 is achieved when discharged at 0.1 and 2 A g−1, respectively, from the core-shell structures.