An investigation was made of the properties of modulation-doped pseudomorphic heterostructures which contained embedded Si -doped GaAs wells. By means of galvanomagnetic and Shubnikov-de Haas measurements, the charge transport parameters were determined before and after optically-induced ionization of DX centers in the structures. A DX center diffusion tail was found which was associated with the -doped donors and which extended into undoped AlGaAs layers. It was concluded that, for efficient modulation doping of a quantum well, -doping and embedding of the donors within a GaAs well could reduce, but not entirely eliminate, the effects of DX centers upon charge transport parameters.

A.P.Young, J.Chen, H.H.Wieder: Journal of Vacuum Science and Technology B, 1995, 13[2], 685-8