Effect of electrical conduction on the saturation of electron emission from diamond needles

Single crystal diamond needles are promising structures as point electron sources. However, the low electrical conductivity of diamond limits their application as high brightness electron sources. Here we study numerically the field emission behavior of single crystal diamond needles in order to better explain the link between their low electrical conduction, and phenomena related to the saturation of the Fowler-Nordheim plot such as the non-homogeneous field distribution in the needle. Comparison with experimental results shows that the conduction behavior depends on the diamond geometry. Moreover, the Fowler-Nordheim plot saturation is shown to be affected by the electrostatic environment.