Energy-Band Structure of Strained Indirect Gap Semiconductor: A k. p Method

A strain Hamiltonian Hst, associated with a sps * k. p Hamiltonian Hkp, is used to describe the valence band and the first two conduction bands of a strained indirect semiconductor. Hst takes into account the Bir-Pikus parameters (a, b) used up to now to describe only the Brillouin zone center. The Hkp+Hst Hamiltonian allows one to calculate the energy dispersion all over the Brillouin zone. The method is applied to Si strained on Si1-xGex alloy. We do not use the local (in k space) deformation potentials Ξu and Ξd conventionally used in indirect gap semiconductor to describe the conduction band. The energy band gap, the conduction bands split into the four equivalent in-plane valleys ∆4 and the two valleys along the growth direction ∆2 which result from the above Hkp+Hst Hamiltonian are in very good agreement with other publications