Dielectric permittivity, conductivity and breakdown field of hexagonal boron nitride

In view of the extensive use of hexagonal boron nitride (hBN) in 2D material electronics, it becomes important to refine its dielectric characterization in terms of low-field permittivity and high-field strength and conductivity up to the breakdown voltage. The present study aims at filling this gap using DC and RF transport in two Au-hBN-Au capacitor series of variable thickness in the 10-100 nm range, made of large high-pressure, high-temperature (HPHT) crystals and a polymer derivative ceramics (PDC) crystals. We deduce an out-of-plane low field dielectric constant epsilon (parallel to) = 3.4 +/- 0.2 consistent with the theoretical prediction of Ohba et al, that narrows down the generally accepted window epsilon (parallel to) = 3-4. The DC-current leakage at high-field is found to obey the Frenkel-Pool law for thermally-activated trap-assisted electron transport with a dynamic dielectric constant epsilon (parallel to) similar or equal to 3.1 and a trap energy phi( B ) similar or equal to 1.3 eV, that is comparable with standard technologically relevant dielectrics.