Electrothermal Simulation of Reverse‐Bias and Hot‐Spot Behavior in Perovskite/Silicon Tandem Modules Under Partial Shading

Partial shading represents a critical reliability challenge for two‐terminal monolithic perovskite/silicon tandem modules, where reverse‐bias and elevated temperature may occur simultaneously in shaded cells. Here, we investigate the coupled electrical and thermal behavior of shaded tandem cells using a combined electrical–optical–thermal simulation framework. Representative IV characteristics are considered for both perovskite and silicon subcells. The simulations show that, for a tandem cell with a silicon subcell characterized by a high breakdown voltage and low reverse‐bias leakage current, the reverse‐bias voltage across the perovskite subcell can be limited to approximately 1 V under partial shading. However, significant hot‐spot temperatures may still arise at the module level. For a typical 120 half‐cell module layout (M10 wafers, 3 bypass diodes, and 20 cells per string), peak hot‐spot temperatures can exceed 190 °C. The hot‐spot temperature increases with the number of cells per string, ambient temperature, and cell efficiency. By contrast, for module layouts with four cells per string, peak temperatures can be kept below 100 °C even under extreme conditions (ambient temperature of 45 °C and cell efficiency of 33%). This work provides characteristic temperature ranges relevant for assessing reverse‐bias‐induced and temperature‐induced degradation in perovskite/silicon tandem modules.