Mumbai university > FE > SEM 1 > Applied Physics 1

Marks: 4M

Year: Dec 2014

The effective mass is a quantity that is used to simplify band structures by constructing an analogy to the behavior of a free particle with that mass. OR mass one can call it as rest mass of an electron. Effective mass of electrons or holes is calculated as:

$m∗ = h2 (4π2) d2Edk2$

Now, if i look at this plot for example:

I can see that for the holes (they should be on the blue part because they belong to the valence band), the absolute value of the curvature d2Edk2 is smaller than the one for the electrons (red part). So, because the effective mass is inversely proportional to that curvature, the effective mass of holes should be larger than the electron’s one.