Ultrathin MoO2 nanosheets with good thermal stability and high conductivity

Abstract

Exploration and development of new two-dimensional (2D) materials with good stability and remarkable physical properties have become the research hotspots. We report for the first time the monodispersity of ultrathin MoO2 nanosheets have been synthesized through an improved chemical vapor deposition (CVD) method using only molybdenum trioxide as precursor. The grown MoO2 nanosheets have an average thickness of ∼ 5 to 10 nm and exhibit good crystal-quality. Temperature-dependent Raman spectra show that the ultrathin MoO2 nanosheets have high thermal stability up to 503 K. In addition, the first order temperature coefficients of the MoO2 characteristic Raman modes O1–Mo and O2–Mo were firstly found to be -1.91×10-2 and -3.94×10-2 cm−1/K, respectively. Two-probe electrical measurements show that the as-fabricated ultrathin MoO2 nanosheets devices preserve a high electrical conductivity in ambient conditions, reaching up to 200 - 475 S/cm. The exceptionally high conductivity of individual MoO2 nanosheet is ascribed to the unique crystal structure. Our results demonstrate that the ultrathin MoO2 nanosheets show great potential applications in constructing new integrated electronic devices and systems.