15 / 2021-05-23 11:25:17

Quantum Space Charge Limited Regime of Field Emission in a Nanogap

Field emission play a significant role in various types of micro-nano power electronic equipment, while quantum space charge modified field emission dominates in a nanogap when the spacing and voltage tend to de Broglie wavelength and Hartree level, respectively. We use a quantum model to calculate one dimension field emission current density in a nanogap, including space charge limited effect and exchange correlation effect. We found that within a certain range of voltage and gap distance, the emission current density will exceed the maximum emission current density calculated by the classical Child-Langmuir (CL) law. In this quantum space charge limited regime, space charge limited effect and exchange correlation effect both are remarkable. The smooth transition between quantum space charge limited regime and classical space charge limited regime is demonstrated.