Nano-Heteroarchitectures of Two-Dimensional MoS@ One-Dimensional Brookite TiO Nanorods: Prominent Electron Emitters for Displays.

We report comparative field electron emission (FE) studies on a large-area array of two-dimensional MoS-coated @ one-dimensional (1D) brookite (β) TiO nanorods synthesized on Si substrate utilizing hot-filament metal vapor deposition technique and pulsed laser deposition method, independently. The 10 nm wide and 760 nm long 1D β-TiO nanorods were coated with MoS layers of thickness ∼4 (±2), 20 (±3), and 40 (±3) nm. The turn-on field ( ) of 2.5 V/μm required to a draw current density of 10 μA/cm observed for MoS-coated 1D β-TiO nanorods emitters is significantly lower than that of doped/undoped 1D TiO nanostructures, pristine MoS sheets, MoS@SnO, and TiO@MoS heterostructure-based field emitters. The orthodoxy test confirms the viability of the field emission measurements, specifically field enhancement factor (β) of the MoS@TiO/Si emitters. The enhanced FE behavior of the MoS@TiO/Si emitter can be attributed to the modulation of the electronic properties due to heterostructure and interface effects, in addition to the high aspect ratio of the vertically aligned TiO nanorods. Furthermore, these MoS@TiO/Si emitters exhibit better emission stability. The results obtained herein suggest that the heteroarchitecture of MoS@β-TiO nanorods holds the potential for their applications in FE-based nanoelectronic devices such as displays and electron sources. Moreover, the strategy employed here to enhance the FE behavior via rational design of heteroarchitecture structure can be further extended to improve other functionalities of various nanomaterials.