CONDUCTION BAND IN SILICON: NUMERICAL VERSUS ANALYTICAL TWO-BAND k·p MODEL
نویسندگان
چکیده
A two-band k·p model for the conduction band of silicon is proposed and compared with other band structure models, notably the nonlocal empirical pseudo-potential method and the spds nearest-neighbor tight-binding model. The twoband k·p model is demonstrated to predict results consistent with the empirical pseudo-potential method, and to accurately describe the band structure around the valley minima, including the effective masses and the band non-parabolicity. The tightbinding model, on the other hand, overestimates the gap between the two lowest conduction bands at the valley minima, which results in an underestimation of the non-parabolicity effects. When strain effects are included, the two-band k·p model gives analytical expressions for the strain-dependence of band structure parameters. Shear strain leads to profound changes in the conduction band causing a shift of the valley minima in momentum space and a modification of the effective masses. Also in the strained case, predictions of the two-band k·p model are in good agreement with those of the pseudo-potential method.
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