1：Experimental Design and Method Selection

The study involved the preparation of Al-doped CdS/Si nanoheterostructures by growing Al-doped CdS films on silicon nanoporous pillar array (Si-NPA) through chemical bath deposition (CBD). The structural, electrical, and electroluminescence properties were investigated as a function of [Al]/[Cd].

2：Sample Selection and Data Sources

Samples were prepared with different [Al]/[Cd] molar ratios (0, 0.01, 0.04, 0.07, 0.10, and 0.15) and labeled accordingly. The structural and morphological characteristics were analyzed using XRD, FE-SEM, HR-TEM, and EDS. Electrical properties were measured using a semiconductor characterization system, and EL spectra were measured by a spectrofluorometer.

3：List of Experimental Equipment and Materials

X-ray diffraction (XRD, Panalytical X’Pert Pro), field-emission scanning electron microscopy (FE-SEM, JSM 6700F), high-resolution transmission electron microscopy (HR-TEM, JEM-2100), Energy-Dispersive Spectrometer (EDS), semiconductor characterization system (Keithley 2400), double grating spectrofluorometer (HORIBA Join Yvon, FL3-22).

4：Experimental Procedures and Operational Workflow

Si-NPA was prepared by hydrothermally etching p-type sc-Si wafers. CdS:Al/Si-NPA were fabricated by a CBD method with different [Al]/[Cd] ratios. Samples were annealed at 500 °C in N2 atmosphere. ITO and Al layers were deposited as electrodes. The structure, electrical, and EL properties were then characterized.

5：Data Analysis Methods

XRD patterns were analyzed to determine crystal structure and phase. SEM and TEM images were used to study morphology and microstructure. EDS was used for compositional analysis. Electrical properties were analyzed from J-V curves, and EL spectra were analyzed to study emission properties.