Quantum Yield and Stability Improvement of Two‐Dimensional Perovskite Via a Second Fluorinated Insulator Layer

Aiming at the low luminous-efficiency of two-dimensional (2D) perovskite, its quantum yield (QY) and stability are effectively improved by a fluorinated second insulator layer 3,4-difluoroaniline (F2PA) outside first 2-(2,4-difluorophenyl) ethylamine (FPEA). The QY perovskite with two layers is 3.4-time in contrast counterpart one insulator, which originates from defect suppression reduction exciton Bohr radius layer. optical has extended 1.5-time introduced layer, as an isolation role for inner decomposed products to volatilize outer water molecules penetrate. retained 90% initial properties relative humidity 90%–95% atmosphere 600 h, meanwhile only 50% Two-more fluorine stronger hydrophobicity can account this feature. Adding effective strategy engineer 2D perovskites push forward applications optoelectronic devices.