[ dĭ-plē′shən ] A region in a semiconductor device, usually at the juncture of P-type and N-type materials, in which there is neither an excess of electrons nor of holes. Large depletion regions inhibit current flow.
What happens in depletion region?
A depletion region forms instantaneously across a p–n junction. In a N-side region near to the junction interface, free electrons in the conduction band are gone due to (1) the diffusion of electrons to the P-side and (2) recombination of electrons to holes that are diffused from the P-side.
How is depletion region calculated?
Putting x = 0 in the above equation for electric field and setting the two values of E equal to each other gives: NAxp = NDxn. This equation makes physical sense since it states that the total charge on one side of the junction must be the same as the total charge on the other.
Where does depletion region occur?
The word depletion in English refers to the decrease in the quantity of something. Similarly, in semiconductors, the depletion region is the layer where the flow of charges decreases. This region acts as the barrier that opposes the flow of electrons from the n-side to the p-side of the semiconductor diode.
What causes depletion region?
The depletion region is caused by the diffusion of charges. The holes and the electrons diffusing towards each other combine near the junction. In doing so positive and negative ions are formed. The pair of positive and negative ions at the junction forms the dipole.
How does the depletion region behave?
In the depletion region, an electric field exists that quickly sweeps out electron-hole pairs that may be thermally generated and reduces the equilibrium concentration of the charge carriers to exceedingly low levels. This region, called the depletion layer, behaves as an insulator.
What causes the depletion region?
The depletion region is caused by the diffusion of charges. Because of the concentration gradient holes diffuse from p-side to the n-side across the junction while electrons diffuse from the n-side to the p-side. The holes and the electrons diffusing towards each other combine near the junction.
What is the width of a depletion region?
The physical width of the depletion region in a typical Si diode ranges from a fraction of a micrometer to tens of micrometers depending on device geometry, doping profile, and external bias.
When depletion region is formed?
Movement of electrons to the p-type side exposes positive ion cores in the n-type side while movement of holes to the n-type side exposes negative ion cores in the p-type side, resulting in an electron field at the junction and forming the depletion region.
Why there are no charge carriers in depletion region?
The region depleted of mobile charge carriers is called the depletion region. The depletion region has only positive ions and negative forms due to the diffusion of carriers across the junction of the pn diode.
What is width of depletion region?
400 nm
The width of a depletion region is 400 nm. The intensity of the electric field at the depletion region is 5×105 V/m.
How do you change the width of a depletion region?
The atom, which loses the valence electron at n-side, becomes a positive ion. Hence, the positive ions at n-side and the negative ions at p-side are increased over a given period. This increases the width of depletion region.
What does it mean to be in a depleted zone?
A depleted zone can at times signify the end of the presence of hydrocarbons in a reservoir and thus it can be abandoned since no hydrocarbons can be produced further. Over a period of time, the pressure inside a reservoir declines making hydrocarbons difficult to rise to the surface and thus the oil and gas production rate declines.
How do you find out what flood zone you are in?
Flood zones are indicated in a community’s flood map. Each flood zone describes the flood risk for a particular area, and those flood zones are used to determine insurance requirements and costs. Know your property’s flood risk.
What happens when you zone out for too long?
What Happens When You Zone Out ‘Zoning out’ or ‘spacing out’ are terms used to describe dissociation. Dissociation’s definition: “a mental process that causes a lack of connection in a person’s thoughts, memory and sense of identity.”
How does a depleted zone affect oil production?
In a depleted zone, the intensity of depletion depends on the type of fluid, type of drive used during drilling, drawdown pressure and production rate. However, the interest of an oil E&P organization lies in the extraction of even the last drop of precious hydrocarbons from a drilled location.
