1：Experimental Design and Method Selection:

The study utilized impedance spectroscopy (IS) to investigate the charge accumulation, injection, and transportation across the interface of the charge transporting and emissive layers in solution-processed optoelectronic devices. Electron-only symmetric and full device architectures were explored for QDs with varied shell thickness.

2：Sample Selection and Data Sources:

Three alloyed QDs with the same core size of 7.0 nm and different shell thicknesses (1.0 nm, 2.1 nm, and 3.3 nm) were analyzed.

3：0 nm and different shell thicknesses (0 nm, 1 nm, and 3 nm) were analyzed. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: Chemicals included Cadmium oxide, zinc acetate, sulfur, selenium, trioctylphosphine, oleic acid, oleylamine, dodecanethiol, 1-octadecene, hexadecylamine, glacial acetic acid, methanol, acetone, toluene. Equipment included F-380 fluorescence spectrometer, UV-6100 UV-vis spectrometer, JEL-JEM 2100F transmission electron microscope, spectroradiometer (PR-788), Keithley 2400 power source analyzer, electrochemical workstation (CHI 660D).

4：Experimental Procedures and Operational Workflow:

QDs were synthesized and characterized. Symmetric and full LED devices were fabricated and their performance was evaluated using IS and other characterization techniques.

5：Data Analysis Methods:

The impedance spectra were fitted to an equivalent circuit model to extract parameters such as interfacial capacitance and resistance.