Recent progress in indoor photovoltaics based on all-inorganic perovskites

The rapid proliferation of Internet of Things (IoT) devices, ranging from smart sensors to wearable electronics, has intensified the demand for sustainable energy solutions capable of powering low-power electronics under indoor illumination. In this context, indoor photovoltaics (IPVs) emerge as a promising technology to enable continuous electricity supply for autonomous IoT systems. To maximize energy harvesting efficiency under indoor conditions, IPV absorbers require an optimal bandgap of 1.7–1.9 eV to match the spectral characteristics of indoor environments as well as high defect tolerance to minimize the defect-induced recombination. These requirements position all-inorganic perovskites (AIPs), particularly CsPbI3 and CsPbI2Br, as superior candidates for IPVs compared to conventional silicon absorbers. This review summarizes recent advancements on AIP-based IPVs, which lead to indoor efficiency exceeding 40%, far surpassing conventional silicon cells. This review also examines a series of synergistic efforts toward the AIP-based IPVs with high performance, further discusses the existing challenges and provides multiple perspectives regarding the future optimization of AIP-based IPVs for practical applications.