Space Charge and Resistance Effects on Saturation of Field Emission

Saturation of field emission under a strong applied electric field has been observed experimentally and studied theoretically for decades. Basically, the saturation can be attributed to a substrate effect characterized by a resistance or a space charge effect featured with a reduced surface electric field. In this work, a self-consistent model based on the particle-in-cell method coupled with a circuit modeling is employed to study the saturation of field emission due to these two effects in order to understand the electrical properties influenced and different characteristics caused.