Anderson localization has inspired tremendous effort in exploring underlying physics regarding electron, atom, and photon transport in disordered lattices. However, due to the difficulty in implementing periodic trapping potential for neutral excitons, observing Anderson localization of excitons in disordered semiconductors remains challenging. We report evidence of Anderson localization of Frenkel excitons in the alloyed perovskite nanocrystals that possess high topological and compositional disorder. The broken symmetry-driven constructive interference of scattered exciton wavefunctions around the octahedrons induces strong exciton localization and, consequently, exciton–phonon coupling. This causes significant promotion of the luminescence quantum efficiency from 30% to an impressive 75% owing to enhanced radiative and suppressed nonradiative quantum transition rates. These findings clarify that both Anderson localization and exciton–lattice coupling play key roles in triggering immobility of Frenkel excitons in disordered wide-bandgap semiconductors and guide design of monocomponent warm white light emitters based on highly efficient alloyed perovskite nanocrystals.

中文翻译：

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拓扑和成分无序诱导的激子安德森定位极大地提高了合金钙钛矿纳米晶体的发光量子产率

安德森定位激发了人们在探索有关无序晶格中电子、原子和光子传输的基础物理方面的巨大努力。然而，由于难以实现中性激子的周期性捕获势，观察无序半导体中激子的安德森局域化仍然具有挑战性。我们报告了具有高度拓扑和成分无序性的合金钙钛矿纳米晶体中弗兰克尔激子的安德森局域化的证据。八面体周围散射激子波函数的对称性破缺驱动的相长干涉引起强烈的激子局域化，从而引起激子-声子耦合。由于增强的辐射量子跃迁率和抑制的非辐射量子跃迁率，这导致发光量子效率从 30% 显着提升到令人印象深刻的 75%。这些发现阐明，安德森局域化和激子-晶格耦合在触发无序宽带隙半导体中弗伦克尔激子的固定性方面发挥着关键作用，并指导基于高效合金钙钛矿纳米晶体的单组分暖白光发射器的设计。