MoS 2 nanoflowers and their field-emission properties

Abstract

Elegant three-dimensional ${\mathrm{MoS}}_2$ nanoflowers were uniformly formed via heating a ${\mathrm{MoO}}_2$ thin film in a vapor sulfur atmosphere. Tens to hundreds of petals were self-assembled within a single nanoflower. Each petal, 100–300 nm wide and only several nanometers thick, exhibited a hexagonal structure. The number of petal layers gradually decreased towards the edges, resulting in uniquely thin edges, typically less than 3 nm. The ${\mathrm{MoS}}_2$ nanoflowers appeared to be excellent field emitters displaying a current density of 0.01 and $\text{10\hspace{0.17em}}{\mathrm{mA/cm}}^2$ at macroscopic fields of 4.5–5.5 and 7.6–8.6 V/μm, respectively; the electron field emission was consistent with the Fowler–Nordheim theory.