Titanium Trisulfide Nanosheets and Nanoribbons for Field Emission-Based Nanodevices.

The field emission (FE) properties of TiS₃ nanosheets and nanoribbons, synthesized by direct sulfuration of bulk titanium, are investigated. The nanosheets show an enhanced FE behavior with a low turn-on field of ∼0.3 V/μm, required for drawing an emission current density of ∼10 μA/cm². Interestingly, the TiS₃ nanosheet emitter delivered a large emission current density of ∼0.9 mA/cm² at a relatively low applied electric field of ∼0.4 V/μm. We have estimated the values of the field enhancement factor (β), which are found to be ∼5 × 10⁴ for the TiS₃ nanosheet emitter and ∼4 × 10³ for the nanoribbon emitter. We attribute the superior FE performance to the presence of atomically sharp edges and the reduced thickness of TiS₃, as reflected in the high value of β. In fact, the nanosheet sample presents a higher density of ultrathin layers (∼12 nm-thick), and thus, they have a larger edge to volume ratio than the nanoribbon samples (which are ∼19 nm-thick). The superior FE behavior of TiS₃ nanosheets over nanoribbons makes them a propitious field emitter and can be utilized for various FE-based applications, demanding large emission currents and lower operational voltages. Moreover, the FE current stability recorded on these samples confirms their promising performance. Thus, the present investigation brings out a great promise of TiS₃ nanosheets and nanoribbons as field emitters for vacuum nanoelectronics devices. [ABSTRACT FROM AUTHOR]