A study was made of Al-related DX-like centres in n-type Al-doped ZnSTe epilayers which had been grown, using molecular beam epitaxy, onto GaAs substrates. Deep-level transient spectroscopy, capacitance-voltage measurements and photoconductivity spectroscopy revealed that the behaviours of the Al donors in ZnSTe were similar to that of so-called DX centres in AlGaAs. The optical ionization energies and emission barriers for the 2 observed Al-related DX-like centres were found to be equal to 1.0 and 2.0eV and 0.21 and 0.39eV. It was noted that the formation of Al-related DX-like centres resulted in significant lattice relaxation.

DX-Like Centres in n-Type Al-Doped ZnSTe Grown by Molecular-Beam Epitaxy. L.Lu, K.K.Mak, Z.H.Ma, J.Wang, I.K.Sou, W.Ge: Journal of Crystal Growth, 2000, 216[1-4], 141-6