2.3.3 The Split-Off Band

     Although the split-off band is parabolic, the apparent effective mass in this band will also exhibit a temperature dependence due to the energy displacement at k = 0. The energy of a hole in the third band is given by


       E=Ev   -     A- A                                      (2.20)


where A is the split-off energy (= 0.044eV), and A is one of the inverse mass band parameters. Substituting equation (2.20) into equations (2.11) through (2.13), and then equating to equations (2.6), (2.9) and (2.10) for the split-off band, we obtain


            m 02A~
            m  exp (-3(2.21)
        D3  A3




               A       3/2
                  fT3F2   exp(-E2)d 2
                0

            m   f   T33/2exp(_)d
       m*    0   0                                            (2.23)
       H 3  A      - TA3 C2 e x p (- 2 )d 2 
               MI f  _3 2 C3/2 exp( _ 2)d  2




where c2= c - A/k0T.

     The combined hole density-of-state effective mass can be determined by assuming that the total number of holes   in the valence band is equal to the sum of the holes in the individual bands