Description
Intrinsic breakdown strength ($F_\text{bd}$), as the theoretical upper limit of electric field strength that a material can sustain, plays important roles in determining dielectric and safety performance. The well accepted concept is that a larger band gap ($E_\text{g}$) often leads to a larger intrinsic breakdown strength. In this work, we analytically derive a simplified model of $F_\text{bd}$, showing a linear relationship between $F_\text{bd}$ and the maximum electron density of states ($\text{DOS}_\text{max}$) within the energy range spanning from the conduction band minimum (CBM) to CBM+$E_\text{g}$. Using the Wannier interpolation technique to reduce the cost of calculating the $F_\text{bd}$ for various three- and two-dimensional materials, we find that the calculated $F_\text{bd}$ did not show any simple relationship with band gap, but it behaves linearly with the $\text{DOS}_\text{max}$, consistent with our theoretical derivation. Our work shows that the $\text{DOS}_\text{max}$ is more fundamental than the band gap value in determining the $F_\text{bd}$, thus providing useful physical insights into the intrinsic dielectric breakdown strength and opening directions for improving high-power devices. The dimensional effects on $F_\text{bd}$ has also been revealed that monolayers tend to have larger $F_\text{bd}$ due to reduced screening effects.
