About cookies on this site Our websites require some cookies to function properly (required). In addition, other cookies may be used with your consent to analyze site usage, improve the user experience and for advertising. For more information, please review your options. By visiting our website, you agree to our processing of information as described in IBM’sprivacy statement. To provide a smooth navigation, your cookie preferences will be shared across the IBM web domains listed here.
Publication
Physical Review B
Paper
Theory of the DX center in AlxGa1-xAs and GaAs crystals
Abstract
It is argued that (1) the so-called DX center is a simple substitutional donor which is displaced from its normal, centered, lattice position, (2) its deep state is derived from a triplet of symmetry T2, not A1 as is generally assumed, and (3) the donor displacement, driven by the energy of an occupied antibonding orbital, resembles a strong Jahn-Teller effect but differs because of the large potential barrier between the centered (T2) donor state and the distorted deep state. This model provides a natural explanation for the bulk of the data published on DX centers, especially the large barrier for thermal capture and the far-infrared absorption spectra reported by Theis et al. for the 1s-2p transition in Si-doped AlxGa1-xAs. The far-infrared absorption spectra indicate that the lowest state of symmetry A1 lies where it is expected, about 70 meV below the L conduction-band edge, or nearly 100 meV above the deep DX level. © 1986 The American Physical Society.