1：Experimental Design and Method Selection:

The study involved synthesizing CH3NH3PbCl1.08Br1.92 PNCs using a ligand-assisted precipitation strategy. ECL was generated using a co-reactant pathway with tripropylamine (TPrA) due to decomposition issues in annihilation pathways. Methods included UV-Vis absorption, TEM, XRD, cyclic voltammetry, ECL and PL spectroscopy, fluorescence microscopy, and time-resolved PL measurements.

2：08Br92 PNCs using a ligand-assisted precipitation strategy. ECL was generated using a co-reactant pathway with tripropylamine (TPrA) due to decomposition issues in annihilation pathways. Methods included UV-Vis absorption, TEM, XRD, cyclic voltammetry, ECL and PL spectroscopy, fluorescence microscopy, and time-resolved PL measurements. Sample Selection and Data Sources:

2. Sample Selection and Data Sources: Samples were synthesized PNCs with varying halide compositions (e.g., CH3NH3PbClxBr3-x). Data were collected from these nanocrystals dispersed in solvents or deposited on electrodes.

3：List of Experimental Equipment and Materials:

Equipment included an HP 8452A UV-Vis spectrophotometer, FEI-TF 20 TEM, Bruker D8 Discover XRD, CHI-760C biopotentiostat, Acton SP2500 monochromator with CCD, and Nikon TE2000U microscope. Materials included methylamine, lead chloride, lead bromide, hydrobromic acid, DMF, n-octylamine, oleic acid, TBAPF6, dichloromethane, toluene, and TPrA.

4：Experimental Procedures and Operational Workflow:

PNCs were synthesized, characterized via TEM and XRD, and deposited on glassy carbon electrodes. ECL experiments used a three-electrode cell with potential stepping or cyclic voltammetry in CH2Cl2 with TBAPF6 and TPrA. PL and ECL spectra were collected, and fluorescence lifetimes were measured under laser excitation.

5：Data Analysis Methods:

Data analysis involved calculating quantum yield using reference dyes, determining non-radiative decay rates, and comparing ECL and PL spectra to identify emission mechanisms and surface states.