Spectroscopic Dynamic Digital-Twin Model Reveals Practical Optimization Strategy of SHJ Solar Cells

Owing to their unique bifacial performance, durability to temperature vibration, and tandem compatibility, silicon heterojunction (SHJ) solar cells have attracted growing investment. Practical strategies for further optimization should consider both the power conversion efficiency (PCE) and the marginal gain of PCE, which requires high-fidelity device modeling. Conventional device modeling is often validated by only DC testing (e.g., JV), which is insufficient to capture carrier dynamics. This work establishes a digital twin model of SHJ solar cells, which is validated by both JV and spectroscopic TPV characteristics that carries information of spatiotemporal carrier dynamics. Being able to reproduce both steady-state and transient information, it can quantitatively approach inaccessible quantities (e.g., donor/acceptor defect energy, defect density, and capture cross-section) and correlate these carrier dynamics parameters with device performance. Consequently, through marginal revenue analysis, practical optimization windows were identified with practically observable device performance indicators. Further reductions in charge transport layer defects and c-Si doping concentration offer diminishing returns at significantly increased cost. This digital twin model bridges the gap between idealized simulations and industrial reality, providing a powerful platform for accelerating the development of next-generation photovoltaics.