© 2019 IEEE. For the crystalline silicon (c-Si) heterojunction (HJ) solar cell with the conventional structure, the parasitic absorbance in the window contact layer (WCL) of p-type doped thin film silicon or its alloy (pDTF-Si/A) limits the amount of the short circuit current density (Jsc) generated. In this work, pDTFSi/A is replaced with a transition metal oxide (TMO) of MoOx, WOx, TiOx, NiOx, Cu2Ox. Due to the wide band gaps of TMO materials, the c-Si HJ cells with TMO WCLs have higher Jsc than the conventional c-Si HJ cell under AM1.5 irradiation. The values of the excess charge carrier lifetime and the implied open circuit voltage indicate that WOx provides the best passivation for c-Si.