Energy Tracing of Photovoltaic Cells

Where did the solar energy go in photovoltaic cells in addition to the electricity? Herein, a detailed analytical derivation and numerical investigation on tracing the energy in solar cells (SCs) driven by various mechanisms are presented. Particularly, the critical factors constraining the SC performance are addressed, i.e., the energy and voltage losses. Six categories of intrinsic losses and three categories of potential losses in SCs are identified, in which the sum of Joule and Peltier losses show a constant under a specific bias and can be regarded as a self‐heating effect within SC; moreover, it is strongly dependent with the key material/device parameters, which can be effectively decreased for a realistic (with carrier recombination) SC system so that approaches the limiting efficiency. To bridge the energy loss and the temperature characteristics, an opto–electro–thermal model is developed to accurately mimic the multiphysics responses of SCs. For Si/perovskite and perovskite/perovskite double‐junction SCs, the energy‐tracing study explains the various energy factors limiting the highest efficiency and predicts an efficiency up to 37.5% by an optimal Si/perovskite double‐junction design. The energy‐based study promotes the understanding of the fundamental photovoltaic physics for the possibilities of new photoconversion strategies with higher performances.