Octahedral Distortion Co-Regulation via Dual Strategies toward Luminescence Enhancement for the MA4InBr7 Perovskite Single Crystal.

A series of novel perovskite single crystals are innovatively grown. Aiming to enhance the luminescence performance, octahedral distortion co-regulation via dual strategies for the as-prepared perovskite single crystals is performed. The distortion of the octahedral structure strengthens the electron-phonon coupling and electron localization, resulting in a more stable self-trapped state, which thereby increases the potential for radiative recombination, accompanied by the self-trapped exciton emission. Accordingly, the luminescence spectra of the as-prepared MA4In0.975Sb0.025Br7 single crystal can cover the 450-800 nm range, and the photoluminescence quantum yield is up to 81.25%.