A lack of electron
p-type semiconductor A semiconductor that is missing electrons is called an electron hole.
direct band gap-semiconductor in which the bottom of the conduction band and the top of the valence band occur at the momentum k=0;in the case of d.b.s. energy released during band-to-band electron recombination with a hole is converted primarily into radiation (radiant recombination); wavelength of emitted radiation is determined by the energy gap of semiconductor; examples of d.b.s. GaAs, InP, ZnS, ZnSs, CdS, CdSe etc. indirect bandgap semiconductor --semiconductor in which bottom of the conduction band does not occur at effective momentum k=0, i.e. is shifted with respect to the top of the valence band which occurs at k=0; energy released during electron recombination with a hole is converted primarily into phonon; e.g. Si, Ge, GaP, GaAsp ,Ge etc, .
Ge has higher conductivity than Si. Because at room temperature the electron and hole mobility for Ge is larger than those of Si. Another explanation is the lower band gap of Ge than Si.
All bipolar transistors are light sensitive: photons striking the semiconductor create electron-hole pairs which make the transistor conduct.In ordinary transistors this is an undesirable source of noise, so they are packaged in opaque metal or plastic cases.A phototransistor on the other hand is packaged either in a metal case with a transparent lens or in transparent plastic to let light in.Note: this is not a significant effect with MOS transistors.
Non degenerate semiconductors are those which: -are lightly doped -have less value of electron and hole concentration -violate Pauli's exclusion principle Degenerate semiconductors are those which: -are highly doped -have high value of electron and hole concentration -follow Pauli's exclusion principle
When an electron is displaced in a semiconductor, the hole that is left behind is called an electron hole. Energy can still be conducted because other electrons can and do jump to the space left by a displaced electron.
a. attracted to the negative terminal of the voltage source as an electrons leave its orbit it leave a hole which is promptly filled by another electron. so as electron flow one way the holes flow the opposite direction. in electronics current flow from positive charge to a less positive chargeclassified as a "hole". Although it doesn't really *exist, it is thought to have the same charge as an electron but opposite polarity.
exciton
p-type semiconductor A semiconductor that is missing electrons is called an electron hole.
p-type semiconductor A semiconductor that is missing electrons is called an electron hole.
p-type semiconductor A semiconductor that is missing electrons is called an electron hole.
Electron holes in semiconductor devices play a crucial role in the flow of electrical current. When an electron moves from one atom to another in a semiconductor material, it leaves behind a hole. These holes can move through the material, allowing for the movement of charge and the creation of an electric current. By controlling the movement of electron holes, semiconductor devices can be used in a variety of electronic applications, such as transistors and diodes.
A hole in a semiconductor has a net positive charge because it represents the absence of an electron, which has a negative charge. When an electron moves from its position to fill the hole, it leaves behind a positively charged location or "hole." This movement of electrons creates a current flow in the material.
The two types of current flow in a semiconductor are electron current, which is due to the movement of negatively charged electrons, and hole current, which is due to the movement of positively charged "holes" left behind when electrons move through the crystal lattice.
The majority carrier in p-type semiconductor is the hole. Electron carriers in p-type semiconductor are minority carriers. Minority carriers in any semiconductor are produced mainly by heat. Only at absolute zero temperature would there be no minority carriers.
actually it is the holes which lead to the movement of the electron,as electron moves to the hole's place creating a hole behind.
The formula to calculate hole density in an N-Type semiconductor is (p = \frac{{n_i^2}}{{n}}), where (p) is the hole density, (n_i) is the intrinsic carrier concentration, and (n) is the electron density. This formula is derived from the law of mass action and represents the equilibrium condition where the product of electron and hole concentrations equals the square of the intrinsic carrier concentration in a semiconductor material.