High‐Quality Perovskite Single Crystal Fabrication via Self‐Assembled Microvesicles Assisted Localized Precursor Release

Abstract The supersaturation degree of perovskite precursors is hardly controllable, usually leading to explosive nucleation, which is a great challenge for the solution growth of large‐scale single crystals. In this work, a straightforward strategy is developed to simultaneously achieve precise nucleation control and significant growth acceleration of diverse perovskite single crystals through self‐assembled propyl methacrylate‐polyhedral oligomeric silsesquioxane (PMA‐POSS) microvesicles. The microvesicles encapsulate high concentrations of perovskite precursors and achieve localized release via thermal polymerization‐induced rupture. As the precursor concentration locally surges in the micro‐region, the nucleation number is conspicuously suppressed and the crystal growth rate is expedited almost threefold. More importantly, the as‐fabricated MAPbI 3 single crystal possesses superior crystal quality in comparison with the routinely grown counterpart, which demonstrates a remarkably low trap density of 8.76 × 10 8 cm −3 and an impressive X‐ray response sensitivity of 2.67 × 10 5 µC Gy air −1 cm −2 . This work provides an effective and universal methodology for high‐quality perovskite single crystal fabrication.