van der Waals epitaxy of Mn-doped MoSe2 on mica

Abstract

The magnetic order associated with the degree of freedom of spin in two-dimensional (2D) materials is subjected to intense investigation because of its potential application in 2D spintronics and valley-related magnetic phenomena. We report here a bottom-up strategy using molecular beam epitaxy to grow and dope large-area (cm2) few-layer MoSe2 with Mn as a magnetic dopant. High-quality Mn-doped MoSe2 layers are obtained for Mn content of less than 5% (atomic). When increasing the Mn content above 5%, we observe a clear transition from layer-by-layer to cluster growth. Magnetic measurements, involving a transfer process of the cm2-large doped layers on 100-micron-thick silicon substrate, show plausible proof of high-temperature ferromagnetism of 1% and 10% Mn-doped MoSe2. Although we could not point to a correlation between magnetic and electrical properties, we demonstrate that the transfer process described in this report permits to achieve conventional electrical and magnetic measurements on the doped layers transferred on any substrate. Therefore, this study provides a promising route to characterize stable ferromagnetic 2D layers, which is broadening the current start-of-the-art of 2D materials-based applications.