1：Experimental Design and Method Selection:

The low temperature method was adopted to synthesize all-inorganic cesium lead bromide CsPbBr3 nanocrystals (NCs). DPABr was added from 0 to

2：15 mole fraction in proportion to the amount of oleylamine to improve film-forming and optoelectronic properties. Sample Selection and Data Sources:

CsPbBr3 NCs were synthesized and characterized using various techniques including SEM, AFM, TEM, XRD, FT-IR, XPS, and NMR.

3：List of Experimental Equipment and Materials:

Equipment included JEOL JEM-1400 and JEOL 3010 transmission electron microscope (TEM), ZEISS Crossbeam scanning electron microscope (SEM), Bruker Innova AFM, Princeton Instruments Acton 2150 spectrophotometer, Horiba iHR320 spectrometer, Bruker D8 SSS instrument, Thermo Scientific Nicolet iS-10 spectrometer, Thermo K-Alpha XPS instrument, BRUKER AVANCE III HD 600 MHz NMR, Agilent 4155C semiconductor parameter analyzer, and Ocean Optics USB2000+ spectrometer. Materials included Cs2CO3, OAm, ODE, PbBr2, DPA, OA, HBr, ITO glass substrates, PEDOT:PSS, TFB, and TPBi.

4：Experimental Procedures and Operational Workflow:

CsPbBr3 NCs were synthesized at 90 °C for 30 min, purified, and then characterized. Devices were fabricated with the configuration of ITO/PEDOT:PSS/TFB/CsPbBr3 NCs/TPBi/LiF/Al.

5：Data Analysis Methods:

Data were analyzed using software ImageJ for crystalline size estimation, and various spectroscopic and microscopic techniques for characterization.