High-performance 2D indoor perovskite solar cells via ferroelectric-enhanced carrier separation

Two-dimensional perovskite materials offer tunable bandgaps, strong light absorption, and enhanced stability, which are ideal candidates for indoor photovoltaics (IPVs), yet their overall performance remains constrained by severe recombination caused by defect states. Ferroelectric semiconductors such as BaTiO3, which sustain strong spontaneous polarization fields, promise ultrahigh open-circuit voltages and enhanced photogenerated-carrier separation, yet their integration into perovskite solar cells remains limited. Here, we embed BaTiO3 nanoparticles into 2D perovskite films to reinforce the internal electric field, suppress non-radiative recombination, and facilitate carrier separation under low-light conditions, with transient photovoltage, photoluminescence, and impedance spectroscopy confirming the ferroelectric-field effect. Under 1000 lux LED illumination, optimized devices achieve open-circuit voltages exceeding 0.95 V, fill factors above 82%, and a record indoor power-conversion efficiency of 31.4%. Our findings establish ferroelectric-enhanced carrier separation as a powerful strategy for next-generation ferroelectric–semiconductor hybrid photovoltaics, paving the way for compact, high-efficiency IPV modules in self-powered electronic systems.