Structural and optical properties of quasi-2D GaTe layers grown by molecular beam epitaxy on GaAs (001) substrates

Abstract

Quasi-two-dimensional GaTe layers were grown by molecular beam epitaxy on GaAs (001) substrates at Ts = 450-520°C. The effect of the growth temperature on the GaTe surface morphology has been studied by scanning electron microscopy. It is shown that GaTe layer grown at high Ts = 520°C exhibits pronounced surface relief anisotropy. This sample demonstrates also near band-edge photoluminescence (PL) at T = 11K with the peak energy of ∼1.72 eV, which can be associated with the emission of excitons bound at the acceptor. The nature of 1.45 eV and 1.57 eV peaks appearing in the PL spectra is also discussed in detail.