BAND-EDGE HOLE MASS IN STRAINED-QUANTUM-WELL STRUCTURES

An analytical expression for the hole mass at the top of the valence band was derived for a strained quantum well (QW) grown on a (001) substrate assuming infinite barriers. This expression for the hole mass indicates that the mass value is isotropic in the (001) QW plane even if the warping of the valence band is taken into account. The mass values estimated from this analytical expression were compared with those calculated numerically by treating the boundary conditions exactly at the heterointerface, and the effects of the finite-barrier height and the strain were studied. The comparison of the calculated mass values with the measurements was also discussed.