currents{ insulator_bandgap }¶
\(\mathrm{\textcolor{Aquamarine}{optional}}\)
type: \(\mathrm{real\;number}\)
unit: \(\mathrm{eV}\)
values: \([10^{-6}, \ldots)\)
default: \(1.0\)
This keyword, \(I_{\text{gap}}\), initializes the quasi-Fermi levels following the formula:
\[\text{div} \exp \left( E_{\text{gap}} / I_{\text{gap}} \right) \nabla E_{\text{F}} = 0,\]
where the intrinsic density is assumed to exponentially depend on the band gap \(E_{\text{gap}}\) with \(I_{\text{gap}}\) as a parameter.
A large value (relative to band gap) of \(I_{\text{gap}}\) allows the Fermi level to drop slowly through antire simulation domain. A small value of \(I_{\text{gap}}\) results in the quasi-Fermi levels drop rapidly in barriers and makes it flat in small band gap regions.
Adjusting this keyword can improve convergence by changing the initial conditions for the algorithm.