Define the effective mass of an electron in a crystal Explai

Define the effective mass of an electron in a crystal. Explain physically Why it arises. List one way in which it plays an important role in conduction in semiconductors.

Solution

The effective mass of an electron is the mass it seems to have when moving in a periodic potential over large distances than the lattice spacing . This motion is very different to motion in vacuum. The effective mass is a quantity that is used to simplify band structures by constructing an analogy to the behaviour of free particle with that mass.

It arises due to response of electron to the nuclesr forces of the atoms in its path and also collision with different other electrons.

the effective mass helps to find efficiency of solar cells

or the speed of an Integrated Circuit