Abstract Excellent front surface passivation is one of the key issues for interdigitated back contact (IBC) silicon solar cells. To create a better understanding of passivation properties and find the most important issues when developing passivation schemes for various injection conditions, an advanced simulation model is needed. The software package Sentaurus TCAD is applied in this work. The main input parameters of the model are the interface state density, the amount of fixed charges, the capture cross sections and the activation energies which have been determined experimentally as reported previously. As an example, simulation results of the advanced model of the recombination at the Si-SiNx interface were presented and compared to the measured data.