What is the diffusion length of minority carriers?

The second related parameter to recombination rate, the “minority carrier diffusion length,” is the average distance a carrier can move from point of generation until it recombines.

What is minority carrier diffusion?

When a p-n juction is forward biased, minority carriers are injected into the semiconductors on the two sides of the junction. These minority carriers diffuse about an eventually recombine with the majority carriers. The distribution of the minority carriers is described by the diffusion equation.

How do you find the minority carrier diffusion length?

7.5. The diffusion length of a carrier type in a material can be defined as the average distance that an excited carrier will travel before recombining. The diffusion length can be defined as follows: L D = Dτ , where D is the diffusion coefficient and τ is the lifetime of the excited carrier.

What is the general solution of the minority carrier diffusion equation?

If “all the minority carriers are removed” at a boundary, i.e. by an ohmic contact, p = p0 + Dp = 0, so Dp = -p0.

What is the diffusion length for electrons when the diffusion coefficient is 10cm2 s and the time between collisions is 40s?

What is the diffusion length for electrons when Dn=10cm2/s and τn=40s? =20cm.

What is minority carrier concentration?

The more abundant charge carriers are the majority carriers; the less abundant are the minority carriers. The equilibrium carrier concentration can be increased through doping. The total number of carriers in the conduction and valence band is called the equilibrium carrier concentration.

How is lifetime minority carrier measured?

The most common way of measuring lifetime is with the so-called microwave PCD (µ-PCD) technique. µ-PCD is based on the excess carrier generation by laser pulse, which effects the change in conductivity and thus microwave reflectivity.

What is a minority carrier?

minority carrier injection, in electronics, a process taking place at the boundary between p-type and n-type semiconductor materials, used in some types of transistors. Each semiconductor material contains two types of freely moving charges: electrons (negative charges) and holes (positive charges).

What is R in diffusion coefficient?

Here, k is the Boltzmann constant, μ is the solvent viscosity, and r is the radius of the diffusing particle.

How do you calculate minority carrier concentration?

By using the Law of Mass Action above, the majority and minority carrier concentrations can be expressed in the following equations: n-type: no = ND, po = ni2 / NDp-type: po = NA, no = ni2 / NA where ND: donor atoms concentration NA : acceptor atoms concentration.