1：Experimental Design and Method Selection:

The study uses laser-assisted three-dimensional atom probe tomography (APT) and photoluminescence (PL) spectroscopy to characterize Sn nanocrystals embedded in silicon. APT provides atomic-scale mapping, and PL measures optical emission.

2：Sample Selection and Data Sources:

Samples were grown by molecular beam epitaxy (MBE) with a composite layer of Si, Sn, and carbon on a Si substrate, annealed at 650, 725, and 800 °C for 20 minutes. Six APT samples were prepared from these.

3：List of Experimental Equipment and Materials:

Equipment includes a LaWaTAP atom probe instrument from CAMECA, a ZEISS NVision 40 SEM-FIB instrument for sample preparation, and PL spectroscopy setup with a cryostat and laser excitation. Materials include Si substrates, Sn, and carbon sources for MBE growth.

4：Experimental Procedures and Operational Workflow:

Samples were annealed post-growth, prepared into tip shapes using lift-out and milling in SEM-FIB, and analyzed with APT using UV laser pulses. PL was measured at 16 K with fs laser pulses. Data analysis involved cluster identification algorithms and correction models for APT artifacts.

5：Data Analysis Methods:

APT data were analyzed for Sn atom distributions and nanocrystal composition using nearest-neighbor distance histograms and correction models. PL spectra were integrated over time to assess optical activity.