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

Specific contact resistance (rho(c)) plays a significant role in determining the efficiency of dopant-free heterojunction (DFHJ) silicon solar cells. Existing methods allow accurate measurement of rho(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 rho(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 rho(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.

Automated summary

The paper demonstrates a new method to extract specific contact resistance from the minority carrier collection region by using the expanded Cox and Strack method. By utilizing technology computer-aided design and a double equivalent circuit model, the method can separate electron and hole current densities, effectively determining the corresponding resistance for both polarities. The effectiveness of this improved method is further validated through experimental examples, establishing a general method for accurately extracting specific contact resistance in DFHJ silicon solar cells.