The adsorption state and the evolution of field emission properties of graphene edges at different temperatures

We have studied the effects of adsorbates on the field emission (FE) properties of graphene edges at different temperatures using Joule heating. Using infrared imaging and spectral fitting, the temperature from room temperature to about 1000 K was measured accurately. It was found that adsorption induces the deviation of graphene edge field emission from the Fowler–Nordheim law and the noise of the field emission. The adsorbates are gradually desorbed with an increase in temperature, and are almost completely desorbed above about 500 K. The FE of graphene edges without adsorption is fairly consistent with the FN theory.