This article presents recent approaches for achieving high conversion efficiency of crystalline silicon solar cells at Delft University of Technology. The new approaches are based on heterojuction interfaces between the crystalline silicon (c-Si) absorber and carrier-selective passivating contact layers. We discuss silicon heterojunction solar cells with carrier-selective contact based on thin layers of hydrogenated amorphous silicon (a-Si: H) and on hydrogenated polycrystalline silicon (poly-Si) combined with a ultrathin silicon oxide layer. Both, the application of carrier-selective contacts in c-Si front-back contacted (FBC) and interdigitated back-contacted (IBC) solar cells with different thermal budgets are shown. The best performance was demonstrated with IBC c-Si solar cells with poly-Si carrier-selective passivating contacts with conversion efficiency η=23.0% and short-circuit current density JSC= 42.2 mAlcm².