Solvent-tailored hybrid sequential deposition enables multifunctional perovskite optoelectronic devices

The development of high-performance perovskite optoelectronics via hybrid sequential deposition is frequently constrained by chaotic crystallization kinetics, which induce detrimental structural defects and lattice strain. Herein, we report a rational solvent engineering strategy that overcomes these bottlenecks by modulating the reaction landscape through the strategic optimization of solvent volatility and solubility. By establishing an equilibrium between precursor diffusion and phase transformation, this approach circumvents the formation of unstable intermediate polytypes and facilitates a direct transition to a highly crystalline, orientationally ordered photoactive phase. This solvent-medicated strategy yields thin films characterized by monolithic grain architectures and high vertical stoichiometric accuracy. The resulting mitigation of residual lattice strain and the significant reduction in electronic trap states enable a multi-functionality platform. As a photovoltaic device, the power conversion efficiencies up to 21.1% with exceptional operational stability. Simultaneously, as a photodetector, it exhibits a robust self-powered response with a specific detectivity of 2.23×1012 Jones. The versatility of this methodology is further demonstrated through the integration of a high-resolution 640×512 pixels imaging and visible light communication systems, underscoring the potential of this solvent-mediated crystallization control for the next generation of stable and multifunctional integrated optoelectronics.