Silicon heterojunction solar cells: Optimization of emitter and contact properties from analytical calculation and numerical simulation

► We relate the open circuit voltage and the band-bending in crystalline silicon. ► We calculate the band-bending in the crystalline part of a silicon heterojunction. ► The band-bending is strongly influenced by the work function and density of states. ► A high defect density in the amorphous silicon emitter increases the band bending. ► A high defect density reduces the impact of the contact on the open circuit voltage.