Study of valence intersubband absorption in tensile strained Si/SiGe quantum wells

Abstract

The hole subband structures and effective masses of tensile strained Si/Si1—ZyGey quantum wells are calculated by using the 6×6 k · p method. The results show that when the tensile strain is induced in the quantum well, the light-hole state becomes the ground state, and the light hole effective masses in the growth direction are strongly reduced while the in-plane effective masses are considerable. Quantitative calculation of the valence intersubband transition between two light hole states in a 7nm tensile strained Si/Si0.55Ge0.45 quantum well grown on a relaxed Si0.5Ge0.5 (100) substrates shows a large absorption coefficient of 8400 cm-1., Si/SiGe