Field-emission characteristics and large current density of heavily Si-doped AlN and AlxGa1−xN (0.38⩽x<1)

From a linear relation between the applied bias and the anode–sample distance, the electric field necessary for field emission (FE) can be obtained reproducibly. For heavily Si-doped AlN and AlxGa1−xN (0.38⩽x<1), the band gap (Al-mole fraction, x), Si-dopant density (NSi), and thickness dependences of the field emission are investigated. After optimizing the sample structure, we obtained a FE current density of 0.22 A/cm2 with a 0.3-mm-diameter rod anode from 0.8-μm-thick Si-doped (NSi:1×1021 cm−3) AlN.