This condition node adds a boundary condition for the charge carrier number density. For example, a n = n0 condition specifies the number density of carrier n.

Individually specify the number density for each charge carrier. Select the checkbox for the Carrier to specify the number density, and then enter a value or expression in the corresponding field. To use another boundary condition for a specific carrier, click to clear the checkbox for the number density of that carrier.

Specify boundary conditions other than Number Density for charge carriers that were cleared above. Choose from the list: No diffusive flux, Open boundary, or No flux.

To display this section, click the Show More Options button () and select Advanced Physics Options. You can find details about the different constraint settings in the section Constraint Reaction Terms in the COMSOL Multiphysics Reference Manual