The front surface design of crystalline silicon solar cells imposes numerous requirements on the electrical and optical properties of its materials. Dopant-free materials with wide-bandgaps represent a promising approach to reduce parasitic absorption and enhance photocurrent extraction. However, the application of dopant-free carrier selective contact layers necessitates systematic physical mechanism analysis of their upper and lower interfaces (passivation layer, metallization electrode, and antireflective coating), along with process-coordinated optical and electrical optimization. Additionally, copper-plated metallization grids are regarded as the mainstream technological approach for achieving cost reduction and efficiency enhancement in solar cells. However, wide-bandgap dopant-free materials, primarily oxides and fluorides, exhibit poor solution resistance or conductivity, rendering them incompatible with copper plating processes. This work employs electron beam evaporated TiO_xN_y films as a dopant-free electron-selective contact layer, featuring a wide bandgap (3.59 eV), low work function (4.27 eV), and low resistivity (1.3 Ω·cm). Due to TiO_xN_y's low resistivity, copper plating metallization can be directly applied in a onestep onto the TiO_xN_y layer. The optimal contact resistance reached 17.9 mΩ·cm², yielding cell performance with a conversion efficiency of 23.01%, open-circuit voltage of 712.9 mV, current density of 39.36 mA/cm², and fill factor of 82.02%. Systematic characterization and physical mechanism analysis demonstrate that the enhanced device efficiency stems from: (1) Replacing n-type hydrogenated amorphous silicon with a dopant-free, electron-selective contact material effectively reduces parasitic absorption; (2) Optimizing the copper plating process significantly improves copper grid line contact to enhance contact resistivity. This provides a novel solution combining dopant-free materials and copper plating for low-cost, high-efficiency heterojunction crystalline silicon solar cells.