What is DP in semiconductor?

Diffusion current Density is a current in a semiconductor caused by the diffusion of charge carriers (holes and/or electrons). This is the current which is due to the transport of charges occurring because of non-uniform concentration of charged particles in a semiconductor.

What is DP in diffusion?

The diffusion current density can be calculated by equation 1. 1. Where e− = −1.602·10−19C is the elemental charge. Dp,n are the diffusion constants for hole and electrons, respectivly.

What is drift current density?

The current caused by the movement of charge carriers either by free electrons or holes per square unit area is referred to as the density of the drift current or Drift current Density. The density is variable based on its type of charge carriers.

What is minority carrier diffusion length?

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 ND in semiconductor?

Nd : concentration of donor atoms. Na : concentration of acceptor atoms. Nd. + : concentration of positively charged donors (ionized donors)

Semiconductors, Insulators

What is NC in semiconductor?

n = Nc exp[-(Ec-EF)/kT] , where Nc is a temperature dependent constant, called the Effective density of states in the conduction band of the semiconductor. Note that Ec is the edge of conduction band Energy and EF is the Fermi energy level (which appears in the Fermi-Dirac distribution function)

What is Ne NH and Ni in semiconductor?

In intrinsic semiconductors, the number of free electrons, ne is equal to the number of holes, nh. T hat is ne = nh = ni, where ni is called intrinsic carrier concentration.

What is carrier diffusion length?

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 carrier drift?

When an electric field is applied across the semiconductors, the carriers drift through the semiconductors. The carriers move with a constant drift velocity. The drift current in a semiconductor is caused due to the carrier drift.

What is neutron diffusion length?

The physical meaning of the diffusion length, L, can be seen by calculating the mean square distance that a neutron travels in the one direction from the plane source to its absorption point.

What causes drift current?

Drift current is caused by electric fields. Diffusion current is caused by variation in the carrier concentration. Direction of the drift current is always in the direction of the electric field. Direction of the diffusion current depends on the gradient of the carrier concentration.

What is hole effect?

The Hall effect is when a magnetic field is applied at right angles to the current flow in a thin film where an electric field is generated, which is mutually perpendicular to the current and the magnetic field and which is directly proportional to the product of the current density and the magnetic induction.

What is drift in semiconductor?

Drift is, by definition, charged particle motion in response to an applied electric field. When an electric field is applied across a semiconductor, the carriers start moving, producing a current.

What is depletion layer in semiconductor?

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 is drift and diffusion?

Drift current is electric current due to the motion of charge carriers under the influence of an external electric field while diffusion current is electric current due to the diffusion of carriers leading to a change in carrier concentration.

What is carrier concentration gradient?

When a carrier concentration gradient exists in the semiconductor, through random motion, carriers will have a net movement from areas of high carrier concentration to areas of low concentration by the process of diffusion. With time, these carriers will diffuse throughout the cell until the concentration is uniform.

What is the Hall mobility?

[′hȯl mō′bil·əd·ē] (solid-state physics) The product of conductivity and the Hall constant for a conductor or semiconductor; a measure of the mobility of the electrons or holes in a semiconductor.

What is difference between drift and diffusion current?

Diffusion current = the movement caused by variation in the carrier concentration. Drift current = the movement caused by electric fields. Direction of the diffusion current depends on the slope of the carrier concentration. Direction of the drift current is always in the direction of the electric field.

What is diffusion in pn junction?

As a result, the charge density of the P-type along the junction is filled with negatively charged acceptor ions ( N_A ), and the charge density of the N-type along the junction becomes positive. This charge transfer of electrons and holes across the PN junction is known as diffusion.

What is diffusion distance?

The diffusion distance is considered as an average length of paths connecting two points on the shape within m steps (i.e. times). In fact, the diffusion distance is computed by embedding a 3D shape into a Euclidean space (i.e. diffusion map) in which the Euclidean distance is equal to the diffusion distance d _m .

What is diffusion time?

The diffusion coefficient determines the time it takes a solute to diffuse a given distance in a medium. D has the units of area/time (typically cm²/s). Its value is unique for each solute and must be determined empirically.

Is diffusion length constant?

The diffusion length is the average distance that the excess carriers can cover before they recombine. Diffusion length depends on the lifetime and mobility of the carriers. Note: Diffusion factor (D) is not a constant, but depents on the carrier mobility.

What is NB in semiconductor?

quasi-neutral base region, NB is the net dopant concentration in the base, and WB is the width of the quasi- neutral base region.

What is hole concentration?

Hole concentration in the P layer under the gate electrode is enhanced due to hole accumulation, similar to the conductivity modulation of a PIN diode, lowering the on-state voltage and increasing the efficiency specially in high-voltage devices.

How do you know if type is N or p?

The easiest would be judging form the periodic table. If the dopant has more electrons in the outer shell than the semiconductor material, it's going to be n-type, and with less electrons in the outer shell, it's p-type.