Hydrothermal synthesis of rGO–PbBi₂Se₄ composite and investigation of its structural, chemical and field emission properties

In the present study we report the one step facile synthesis of pristine lead bismuth selenide (PbBi₂Se₄) and reduced graphene oxide (rGO) and its composites with PbBi₂Se₄. Formation of pristine PbBi₂Se₄ and rGO–PbBi₂Se₄ composite were confirmed by X-ray diffraction and X-ray photoelectron spectroscopy. The surface morphology and topography investigated by using scanning electron microscopy and transmission electron microscopy revealed the formation of nano-flowers pristine PbBi₂Se₄. After coupling pristine PbBi₂Se₄ with rGO the surface morphology shows the formation of sharp vertically protruded nano-sheets/nano-flaks originated from the nano-flowers. Finally, the field emission properties of pristine PbBi₂Se₄ and rGO–PbBi₂Se₄ composite have been investigated. It has been observed that the rGO–PbBi₂Se₄ composite emitter exhibited excellent field emission properties with low turn-on field (~ 2.8 V/µm for 10 µA/cm²), high emission current density (~ 1288 µA/cm² at 3.9 V/µm) and superior current stability (~ 4.5 h for ~ 1 µA) compare to pristine PbBi₂Se₄ emitter. Thus, the facile one step synthesis approach and robust nature of rGO–PbBi₂Se₄ composite emitter can provide prospects for the future development of large-area emitter applications such as flat-panel-display and vacuum micro/nanoelectronics devices.