Metal-Free Hybrid Organic-Inorganic Perovskites for Photovoltaics.

There has been intense interest in hybrid organic-inorganic perovskites (HOIPs) in the materials science community due to their unexpected and fascinating properties with respect to photovoltaic applications. The intrinsic toxicity of Pb-based HOIPs, however, seriously hinders its practical large-scale commercialization. Exploring novel stable and environmentally friendly high-performance HOIPs for sunlight harvesting therefore becomes a scientific research hotspot in the photovoltaic research community. In contrast to devoting a great amount of effort to searching promising metal-cation-based HOIPs for photovoltaics, a comprehensive investigation of a series of silicon-based HOIPs is carried out in this study to discover metal-free high-performance HOIPs for photovoltaics. Remarkably, a new family of unexplored metal-free HOIPs with promising electronic properties for solar cells, theoretically confirmed to possess excellent thermal and environmental stability, is eventually discovered and expected to be tested for further experimental synthesis and characterization. The present study marks a significant step toward discovering a series of novel metal-free HOIPs for photovoltaics and provides novel cognition for rational design regarding eco-friendly and environmentally friendly materials.