n=DDGelectron_driftdiffusion(mesh,Dsides,nin,pin,V,un,tn,tp,n0,p0,weight) IN: V = electric potential mesh = integration domain nin = electron density in the past + initial guess pin = hole density in the past n0,p0 = equilibrium densities tn,tp = carrier lifetimes weight = BDF weights un = mobility OUT: n = updated electron density