Realization of a General Method for Extracting Specific Contact Resistance of Silicon‐Based Dopant‐Free Heterojunctions

Specific contact resistance ( ρ C ) plays a significant role in determining the efficiency of dopant‐free heterojunction (DFHJ) silicon solar cells. Existing methods allow accurate measurement of ρ C only in the majority carrier collection region. Herein, taking the heterojunctions of transition metal oxide/c‐Si(n) as an example, how to extract ρ C from the minority carrier (hole) collection region by ingeniously using the expanded Cox and Strack method is demonstrated. On the basis of technology computer‐aided design and a double (diode + resistance) equivalent circuit model, the improved method can separate the electron current density and hole current density from each other and thus the corresponding resistance for both polarities can be well determined. The effectiveness of the improved method in precisely extracting the corresponding ρ C is further verified by a series of experimental examples. A general method of unambiguously extracting specific contact resistance in DFHJ silicon solar cells is established.