1：Experimental Design and Method Selection:

The study involved designing 2D-3D perovskites by incorporating sodium bromide (NaBr) as a spacer to replace organic cations. Methods included spin-coating precursor solutions, annealing, and various characterizations like GIXRD, UV-Vis, PL, and device fabrication.

2：Sample Selection and Data Sources:

Perovskite films were prepared with different molar ratios of NaBr (x from 0% to 70%) in precursor solutions containing CsBr, PbBr2, and NaBr in DMSO. An organic additive (crown) was used to improve film quality.

3：List of Experimental Equipment and Materials:

Equipment included spin coaters, SEM (Carl Zeiss Supra 55), AFM (Cypher S), DLS (Nano-ZS90 Malvern), UV-Vis spectrometer (SPECORD S 600), PL spectrometer (IHR 320 Horiba), FLIM system, XRD (Bruker D8 Advance), GIXRD at Shanghai Synchrotron Radiation Facility, FTIR (Vertex-70), UPS system, and LED testing setups (Keithley 2400, PhotoResearch PR670). Materials included PbBr2, CsBr, NaBr, DMSO, crown, TFB, PVK, TPBi, LiF, Al, and others from suppliers like Alfa Aesar, Sigma Aldrich, etc.

4：0). Materials included PbBr2, CsBr, NaBr, DMSO, crown, TFB, PVK, TPBi, LiF, Al, and others from suppliers like Alfa Aesar, Sigma Aldrich, etc. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Precursor solutions were prepared by dissolving chemicals in DMSO, stirred at 60°C, filtered, and spin-coated on substrates. Films were annealed at 100°C. LED devices were fabricated with layered structures including ITO, TFB/PVK, perovskite, TPBi, LiF/Al. Characterizations involved optical, structural, and electrical measurements.

5：Data Analysis Methods:

Data were analyzed using software like FIT2D for GIXRD, phasor plots for lifetime analysis, impedance spectroscopy for dielectric constants, and statistical methods for device performance.