Close‐to‐Equilibrium Crystallization for Large‐Scale and High‐Quality Perovskite Single Crystals

Abstract The growth of large semiconductor crystals is crucial for advancing modern electronics and optoelectronics. While various crystal growth techniques have been developed for lead halide perovskites, a significant challenge remains: as crystal size increases, performance tends to deteriorate dramatically. This study addresses the inherent limitations of perovskite crystal growth by designing a novel strategy for near‐equilibrium growth system to maintain optimal conditions throughout the process. The system consists of three independent units: a solution supply unit, a crystal growth unit, and a solution recycling unit, which together ensure a constant solution concentration and temperature. By systematically optimizing temperature control and solution feeding rates, large and high‐quality FAPbBr 3 single crystals, including a notable crystal measuring 51 × 45 × 10 mm 3 are successfully produced. This crystal demonstrates a mobility‐lifetime product of 2.83 × 10⁻ 2 cm 2 V⁻¹ and an ultralow detection limit of 319.22 pGy air , significantly surpassing existing perovskite crystals of similar size. The approach can serve as a universal platform for the controlled synthesis of all kinds of perovskite single crystals, laying the foundations for their use in various optoelectronic applications.