Tandem solar cell with dual capability of indoor–outdoor application — A numerical calculation study

This study explores the conceptual development of an innovative tandem solar cell aimed at maximizing efficiency in both indoor and outdoor settings. Traditional tandem solar cells predominantly utilize a 2-terminal in-series architecture, which presents significant challenges related to current matching particularly for applications that span both environments. We investigate the potential of a parallel-series connection configuration for 2-terminal tandem cells for optimal usage both in outdoor and indoor conditions. Our findings demonstrate that this approach is not only robust against current mismatch but also allows for the optimization of absorber band gap energies. We present case studies comparing the performance of state-of-the-art solar cells across various technologies, highlighting the advantages of both in-series and in-parallel connections. Additionally, we conduct calculations to assess the current mismatch in subcells, underscoring the benefits of the parallel-series configuration for dual outdoor-indoor applications. We show that while the power conversion efficiency (PCE) of in-series tandem reduces in indoor application, parallel-series tandem demonstrates increasing in PCE by increasing of in-door light intensity. Additionally, by employing cutting-edge solar cells, we calculate a PCE for the in-series tandem configuration using a Perovskite/copper indium gallium selenide (CIGS) combination, and for the parallel-series tandem configuration with a Perovskite/c-Silicon pairing. The results demonstrate that the parallel-series tandem achieves a PCE comparable to that of the in-series tandem, while offering greater tolerance to current mismatches.