Determination of the density of states in heavily doped regions of silicon solar cells

In highly doped crystalline silicon, the formation of an impurity band substantially changes the density of states (DOS) of electrons. As yet, heavily doped silicon has been modelled using solely the ideal DOS of undoped silicon, regardless of the doping density. Since this approximation influences the position of the Fermi energy, we derive a more realistic silicon DOS model that is suitable for numerical device simulations. Our new model is based on photoluminescence data reported in the literature and a recently published bandgap narrowing model.