1：Experimental Design and Method Selection:

The growth of CdTe epitaxial layers on SrTiO3 (001) substrates by molecular beam epitaxy (MBE) was monitored in situ by reflection high energy electron diffraction (RHEED). The crystalline structures were characterized by X-ray diffraction (XRD), and the lattice parameters were revealed by reciprocal space mapping, electron microscopy, and electron diffraction.

2：Sample Selection and Data Sources:

SrTiO3 (001) substrates were degreased, etched, and annealed before loading into the MBE chamber. CdTe and Te sources were evaporated from standard Knudsen cells.

3：List of Experimental Equipment and Materials:

MBE system (Riber 32P), RHEED (STAIB Instruments NEK300R3–8), XRD (Bruker D8), AFM (Veeco Dimension 3100), TEM (JEM-2100F), PL spectrometer (Bruker IFS 80 V/S).

4：Experimental Procedures and Operational Workflow:

Substrate temperatures ranged from 200 to 280 °C were applied to grow the CTELs. The growth processes were monitored by RHEED. The structural quality and surface morphologies were characterized by XRD and AFM, respectively. Cross-section samples were prepared for TEM analysis. PL spectra were measured at 5 K.

5：Data Analysis Methods:

The evolution of the inter-atomic distances was deduced from RHEED. The lattice parameters and epitaxial relationships were determined by XRD and TEM. The PL spectra were analyzed to study the possible defects.