Unveiling the degraded electron durability in reduced-dimensional perovskites.

The operational stability of reduced-dimensional metal halide perovskites (RD-MHPs) lags far behind the practical requirements for future high-definition displays. Thereinto, the electron durability of RD-MHPs plays a critical role in stable LEDs during continuous operation, however, it still lacks adequate research and a deep understanding. Herein, the electron durability and deterioration mechanism of phenethylammonium (PEA + )-modified RD-MHPs are systematically conducted through an in situ photoelectron spectroscopy technique by implementing tunable electron-beam radiation to simulate device operation. The formation of detrimental metallic lead (Pb 0 ) caused by the reduction of lead ions (Pb 2+ ) is observed along with the decomposition of PEA + under electron-beam radiation, thereby changing the photophysical properties of PEA + -doped RD-MHPs. These results provide deep insight into the process of how injected electrons affect the performance of PEA + -doped perovskite LEDs, which may also provide potential guidance for designing robust and effective organic spacers for RD-MHPs.