On the other hand, majority carriers are driven into the drift region by diffusion ( resulting from the concentration gradient ), which leads to the forward current; only the majority carriers with the highest energies ( in the so-called Boltzmann tail; cf.
32.
Electrons which diffuse from the cathode into the P-doped layer, or anode, become what are termed " minority carriers " and tend to recombine there with the majority carriers, which are holes, on a timescale characteristic of the material which is the p-type minority carrier lifetime.
33.
The power MOSFET has the advantages of a majority carrier device, so it can achieve a very high operating frequency, but it cannot be used with high voltages; as it is a physical limit, no improvement is expected in the design of a silicon MOSFET concerning its maximum voltage ratings.
34.
Recombination can occur by direct encounter with a majority carrier, annihilating both carriers, or through a LED recombination of electrons and holes is accompanied by emission of light of a wavelength related to the energy gap between valence and conduction bands, so the diode converts a portion of the forward current into light.
35.
As recombination takes hold, the minority carrier densities drop with depth to their equilibrium values for bulk minority carriers, a factor exp ( " " & phi; B " / " V th " ) smaller than their bulk densities " n B ", " p B " as majority carriers before injection.
36.
The gradient driving this transfer is set up as follows : in the bulk distant from the interface, minority carriers have a very low concentration compared to majority carriers, for example, electron density on the " p "-side ( where they are minority carriers ) is a factor lower than on the " n-" side ( where they are majority carriers ).
37.
The gradient driving this transfer is set up as follows : in the bulk distant from the interface, minority carriers have a very low concentration compared to majority carriers, for example, electron density on the " p "-side ( where they are minority carriers ) is a factor lower than on the " n-" side ( where they are majority carriers ).
