# What is the formula for effective mass of hole?

## What is the formula for effective mass of hole?

The conduction electrons occupy the conduction band minimum and tbhe holes occupies the conduction band maximum. The E-p relation at the conduction band minimum can be well fitted by a parabolic relation of the form: E-E= p^2/2me* where me* is the effective mass of the electrons in the condcution band.

### Is effective mass of holes negative?

the bubble always moves the opposite way from what you would expect of a particle with mass, i.e. it moves with negative mass. A hole in a semiconductor thus moves with the opposite of the negative electron mass, i.e. as if it has a positive effective mass. Instead we have holes with positive effective mass.

How do you calculate effective mass in physics?

This mass of an electron is called the effective mass of an electron, denoted as m*. The effective mass is thus determined by d 2E/dK 2.

Can a hole have mass?

The electrons that are missing have a negative effective mass. So the holes have a positive effective mass.

## What is meant by effective mass?

In solid state physics, a particle’s effective mass (often denoted. ) is the mass that it seems to have when responding to forces, or the mass that it seems to have when interacting with other identical particles in a thermal distribution.

### What are ek diagrams?

An E-k diagram shows characteristics of a particular semiconductor material. It shows the relationship between the energy and momentum of available quantum mechanical states for electrons in the material.

Is effective mass positive or negative?

As one can see from the dispersion curves, the effective mass of the electrons in the valence band, m*V, is always negative. (This means that a force in +x direction will cause such an electron to move in –x direction.)

What is a negative effective mass?

The negative effective mass tells you that the electron responds to the field opposite to how a free electron would. Physically, the fact that the electron accelerates opposite to the direction of the force is because the electron must reflect off the zone boundary. As it approaches the boundary, it must decelerate.

## What do you mean by effective mass?

### What are heavy holes and light holes?

As the names say heavy holes are in the heavy hole band and light holes in the light hole band, meaning the effective mass m* of heavy holes mhh is larger than of light holes mlh. Thus holes respond with two different speeds to electric field, meaning light holes are/respond faster than heavy holes.

Are holes protons?

When we say “lack of electrons,” we really mean “initially neutral atom, then an electron is removed, leaving an exposed, un-cancelled proton; a positive ion.” Holes are actually the un-cancelled protons of the silicon crystal lattice. They really are positive-charged particles.

Can holes be created in metal?

Vacancy of electron created in the valance band of solid due to the upward transition of electron is called hole. It can do so only by changing its energy level and hence holes are not generated in metals. …

## How to calculate the mass of a light hole?

For Si, we compute a light hole mass (at the Γ point [0,0,0]) m∗ LH = −0.16 m L H ∗ = − 0.16 (band index=1), and for the two degenerate heavy hole bands the result is m∗ HH = −0.25 m H H ∗ = − 0.25 (band indices 2 and 3, respectively).

### Which is larger small or large effective masses?

Large curvatures (= large second derivative = small radius of curvature) give small effective masses, small curvatures (= small second derivative = large radius of curvature) give large ones. Let’s look at what we did in a simple illustration and then discuss what it all means.

How to calculate the effective mass of an electron?

Accordingly we evaluate the electron’s effective mass by separately writing down the expressions for the force on the electron, and its acceleration, and then solving for the electron’s effective mass using equation 44. (45) and (46)

When does the effective mass of a solid go negative?

One remarkable property is that the effective mass can become negative, when the band curves downwards away from a maximum.