Laser exfoliation of 2D black phosphorus nanosheets and their application as a field emitter

Abstract

Highly crystalline two dimensional (2D) few layered black phosphorus (BP) nanosheets have been synthesized via a one step facile laser irradiation technique under optimized experimental conditions. The field emission investigations on the few layered black phosphorus nanosheets were carried out at the base pressure 1 × 10⁻⁸ mbar. The morphological, elemental, optical, and structural analysis of the as-synthesized black phosphorus sample was carried out using SEM, AFM, EDAX, TEM, and Raman spectroscopy. The turn-on values of the BP nanosheets emitter were found to be significantly lower than that of earlier reports of BP nanosheets, graphene, and carbon nanotubes based field emitters due to the high field enhancement factor (β) ∼2986 associated with atomically thin/sharp edges of the BP nanosheets emitter. The emission current versus time plot depicts the good emission current stability with a pre-set value of 1 μA for ∼5 h duration. Our facile synthesis approach and the robust field emitter nature of the BP nanosheets makes them a potential candidate for a practical electron source in vacuum micro/nanoelectronic devices.