An electroreflectance study of CdTe

Electroreflectance measurements are reported for bulk and epitaxial CdTe layers grown by molecular-beam epitaxy (MBE). Spectra are analyzed to determine the E0, E1, and E1+Δ1 transition energies as well as the associated broadening energies. The broadening energies are found to correlate with the structural quality of the epilayers. Additional spectral features near the band edge (1.45–1.51 eV) and in the UV (3.1–4.3 eV) are discussed. The extremely sharp spectra obtained for the MBE-grown epitaxial layers indicate high-quality material.