Strain-induced two-dimensional electron gas in [111] growth-axis strained-layer structures

It is demonstrated that strain-induced electric fields in [111] growth-axis strained-layer structures can be used to induce a two-dimensional electron gas without the necessity of modulation doping. A simple analytic expression is derived for the density of the two-dimensional electron gas. The density has a simple linear relationship to the strain-induced electric fields. The calculation predicts that two-dimensional densities in the range 1011–1012 cm−2 should be easily realized in strained-layer structures. Results are calculated for a variety of material systems.