Optical Optimization Potential of Transparent‐Passivated Contacts in Silicon Solar Cells

Herein, an optical loss analysis of the recently introduced silicon carbide–based transparent passivating contact (TPC) for silicon heterojunction solar cells is presented, the most dominant losses are identified, and the potential for reducing these losses is discussed. Magnesium fluoride is applied as an antireflective coating to reduce the reflective losses by up to 0.8 mA cm−2. When applying the magnesium fluoride, the passivation quality of the layer stack degrades, but is restored after annealing on a hot plate in ambient air. Afterwards, a road map for TPC solar cells toward an efficiency of 25% is presented and discussed. The largest part in efficiency gain is achieved by reducing the finger width and by increasing the passivation quality. Furthermore, it is shown that TPC solar cells have the potential to achieve short-circuit current densities above 42 mA cm−2 if the finger width is reduced and the front-side indium tin oxide (ITO) layer can be replaced by an ITO silicon nitride double layer