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Specifically, drift relates the movement of a carrier (e.g., an electron or hole) to an applied electric field (i.e., the velocity of the carrier is proportional to the electric field, where the proportionality constant, mobility, is a quantity derived in solid-state physics). Diffusion relates the movement of carriers due to random (i.e., thermal) behavior and non-uniform distribution (i.e., the velocity of the carrier is proportional to the logarithmic derivative of the density of carriers, where the proportionality constant, the diffusion constant, is a quantity derived in solid-state physics).

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What is the difference between drift current and diffusion current?

The difference between drift current and diffusion current is that drift current depends on the electric field applied: if there's no electric field, there's no drift current. Diffusion current occurs even though there isn't an electric field applied to the semiconductor. It does not have E as one of its parameters. The constants it does depend on are Dp and Dn, and +q and -q, for holes and electrons respectively. The first constants are called the diffusion coefficients, a proportionality factor. We don't worry too much about these because they are constants. We do worry about the gradient of the concentration of p and/or n, though. But, since we are talking about a one dimensional situation when we are solving for current densities, we only worry about the gradient (or derivative) with respect to the x-plane. The other difference between drift current and diffusion current, is that the direction of the diffusion current depends on the change in the carrier concentrations, not the concentrations themselves. In the equation, the signs are reversed as we are used to seeing them. We usually assign a +q to holes and -q to electrons. In the case of diffusion current, they are reversed to be opposite of the derivative of the concentrations. This occurs because the carriers are diffusing from areas of high concentrations to areas of low concentrations. For example, if the derivative of pwith respect to x is positive, then the concentration of holes is growing as you move towards the +x direction. Diffusion current will be the opposite of that, the holes will be diffusing in the -x direction to where there's a lower concentration of holes. If the derivative is negative, the opposite will occur. The concentration of holes is decreasing as you go from the -x to +x direction. Therefore, holes will diffuse to the +x direction where there's a lower concentration of holes. This is why the negative sign is needed in the equation for the hole diffusion current. The same goes for electrons, but in this case, the signs cancel for a positive derivative because the electrons, carrying -q, diffuse to the -x direction where there's less electrons. The sign remains if the derivative is negative, because electrons will be diffusing to the +xdirection carrying a -q charge. For these reasons it's not included in the equation for the electron diffusion current. source: http://www.ece.utep.edu/courses/ee3329/ee3329/Studyguide/ToC/Fundamentals/CAction/diffusion.html The difference between drift current and diffusion current is that drift current depends on the electric field applied: if there's no electric field, there's no drift current. Diffusion current occurs even though there isn't an electric field applied to the semiconductor. It does not have E as one of its parameters. The constants it does depend on are Dp and Dn, and +q and -q, for holes and electrons respectively. The first constants are called the diffusion coefficients, a proportionality factor. We don't worry too much about these because they are constants. We do worry about the gradient of the concentration of p and/or n, though. But, since we are talking about a one dimensional situation when we are solving for current densities, we only worry about the gradient (or derivative) with respect to the x-plane. The other difference between drift current and diffusion current, is that the direction of the diffusion current depends on the change in the carrier concentrations, not the concentrations themselves. In the equation, the signs are reversed as we are used to seeing them. We usually assign a +q to holes and -q to electrons. In the case of diffusion current, they are reversed to be opposite of the derivative of the concentrations. This occurs because the carriers are diffusing from areas of high concentrations to areas of low concentrations. For example, if the derivative of pwith respect to x is positive, then the concentration of holes is growing as you move towards the +x direction. Diffusion current will be the opposite of that, the holes will be diffusing in the -x direction to where there's a lower concentration of holes. If the derivative is negative, the opposite will occur. The concentration of holes is decreasing as you go from the -x to +x direction. Therefore, holes will diffuse to the +x direction where there's a lower concentration of holes. This is why the negative sign is needed in the equation for the hole diffusion current. The same goes for electrons, but in this case, the signs cancel for a positive derivative because the electrons, carrying -q, diffuse to the -x direction where there's less electrons. The sign remains if the derivative is negative, because electrons will be diffusing to the +xdirection carrying a -q charge. For these reasons it's not included in the equation for the electron diffusion current. source: http://www.ece.utep.edu/courses/ee3329/ee3329/Studyguide/ToC/Fundamentals/CAction/diffusion.html The difference between drift current and diffusion current is that drift current depends on the electric field applied: if there's no electric field, there's no drift current. Diffusion current occurs even though there isn't an electric field applied to the semiconductor. It does not have E as one of its parameters. The constants it does depend on are Dp and Dn, and +q and -q, for holes and electrons respectively. The first constants are called the diffusion coefficients, a proportionality factor. We don't worry too much about these because they are constants. We do worry about the gradient of the concentration of p and/or n, though. But, since we are talking about a one dimensional situation when we are solving for current densities, we only worry about the gradient (or derivative) with respect to the x-plane. The other difference between drift current and diffusion current, is that the direction of the diffusion current depends on the change in the carrier concentrations, not the concentrations themselves. In the equation, the signs are reversed as we are used to seeing them. We usually assign a +q to holes and -q to electrons. In the case of diffusion current, they are reversed to be opposite of the derivative of the concentrations. This occurs because the carriers are diffusing from areas of high concentrations to areas of low concentrations. For example, if the derivative of pwith respect to x is positive, then the concentration of holes is growing as you move towards the +x direction. Diffusion current will be the opposite of that, the holes will be diffusing in the -x direction to where there's a lower concentration of holes. If the derivative is negative, the opposite will occur. The concentration of holes is decreasing as you go from the -x to +x direction. Therefore, holes will diffuse to the +x direction where there's a lower concentration of holes. This is why the negative sign is needed in the equation for the hole diffusion current. The same goes for electrons, but in this case, the signs cancel for a positive derivative because the electrons, carrying -q, diffuse to the -x direction where there's less electrons. The sign remains if the derivative is negative, because electrons will be diffusing to the +xdirection carrying a -q charge. For these reasons it's not included in the equation for the electron diffusion current. source: http://www.ece.utep.edu/courses/ee3329/ee3329/Studyguide/ToC/Fundamentals/CAction/diffusion.html


What relation between electric current and drift velocity?

The drift velocity of free electrons in a conductor is directly proportional to the magnitude of the electric current flowing through the conductor. This means that as the current increases, the drift velocity of the electrons also increases. The relationship is described by the equation I = nAvq, where I is the current, n is the number density of charge carriers, A is the cross-sectional area of the conductor, v is the drift velocity, and q is the charge of the charge carrier.


What is zero drift current?

Zero drift current refers to the small amount of electrical current that flows through an operational amplifier when the input voltage is zero. This current can cause errors in precision measurements because it can create an offset in the output voltage of the amplifier. Minimizing zero drift current is important in applications where accurate and stable voltage measurements are required.


What is the effect on the drift velocity of free electrons by decreasing the length and the temperature of wire?

As we know , resistance(R) is directly proportional to length(L) of conductor and resistence(R) is inversely proportional to current (I) and I=nAqv (v is drift velocity) So , if we decrease the length of the conductor , resistance of the conductor will decrease and current(I) will increase and drift velocity of free electrons will increase . And as we know resistance and temperature have direct relation so , by decreasing the temperature resistence will decrease and current will increase . So drift velocity will increase .


Why it is not possible to measure the drift speed for electron by timing their travel along the conductor?

It's difficult to accurately measure drift speed by timing electrons because individual electrons move randomly at high speeds, making it hard to track their motion. Also, electrons in a conductor have different velocities and directions, making it challenging to calculate an average drift speed. The collective drift speed of electrons in a current can be measured indirectly by observing the overall current flow in the conductor.

Related Questions

Can diffusion current and drift current can exist in a Semi conductors?

Yes.


Does drift current depends on carrier concentration?

no,drift current depends upon electric field where as carrier concentration lead to diffusion current


In an electrode-electrolyte circuit what do the terms drift current and diffusion current mean?

A drift current is electric charges being moved in the presence of an electric field, and a diffusion current is electric charges being moved by a chemical diffusion gradient (where no electric field exists, but where there is a concentration gradient of chemical species driving the current).


What is definition of diffusion current?

The diffusion current in a metal-semiconductor diode is derived based on the assumption that the depletion layer is large compared to the mean free path, so that the concepts of drift and diffusion are valid.


What is the difference between longshore drift and longshore current?

Current is with water and drift is moving sediments in the current


What is the difference between drift current and diffusion current?

The difference between drift current and diffusion current is that drift current depends on the electric field applied: if there's no electric field, there's no drift current. Diffusion current occurs even though there isn't an electric field applied to the semiconductor. It does not have E as one of its parameters. The constants it does depend on are Dp and Dn, and +q and -q, for holes and electrons respectively. The first constants are called the diffusion coefficients, a proportionality factor. We don't worry too much about these because they are constants. We do worry about the gradient of the concentration of p and/or n, though. But, since we are talking about a one dimensional situation when we are solving for current densities, we only worry about the gradient (or derivative) with respect to the x-plane. The other difference between drift current and diffusion current, is that the direction of the diffusion current depends on the change in the carrier concentrations, not the concentrations themselves. In the equation, the signs are reversed as we are used to seeing them. We usually assign a +q to holes and -q to electrons. In the case of diffusion current, they are reversed to be opposite of the derivative of the concentrations. This occurs because the carriers are diffusing from areas of high concentrations to areas of low concentrations. For example, if the derivative of pwith respect to x is positive, then the concentration of holes is growing as you move towards the +x direction. Diffusion current will be the opposite of that, the holes will be diffusing in the -x direction to where there's a lower concentration of holes. If the derivative is negative, the opposite will occur. The concentration of holes is decreasing as you go from the -x to +x direction. Therefore, holes will diffuse to the +x direction where there's a lower concentration of holes. This is why the negative sign is needed in the equation for the hole diffusion current. The same goes for electrons, but in this case, the signs cancel for a positive derivative because the electrons, carrying -q, diffuse to the -x direction where there's less electrons. The sign remains if the derivative is negative, because electrons will be diffusing to the +xdirection carrying a -q charge. For these reasons it's not included in the equation for the electron diffusion current. source: http://www.ece.utep.edu/courses/ee3329/ee3329/Studyguide/ToC/Fundamentals/CAction/diffusion.html The difference between drift current and diffusion current is that drift current depends on the electric field applied: if there's no electric field, there's no drift current. Diffusion current occurs even though there isn't an electric field applied to the semiconductor. It does not have E as one of its parameters. The constants it does depend on are Dp and Dn, and +q and -q, for holes and electrons respectively. The first constants are called the diffusion coefficients, a proportionality factor. We don't worry too much about these because they are constants. We do worry about the gradient of the concentration of p and/or n, though. But, since we are talking about a one dimensional situation when we are solving for current densities, we only worry about the gradient (or derivative) with respect to the x-plane. The other difference between drift current and diffusion current, is that the direction of the diffusion current depends on the change in the carrier concentrations, not the concentrations themselves. In the equation, the signs are reversed as we are used to seeing them. We usually assign a +q to holes and -q to electrons. In the case of diffusion current, they are reversed to be opposite of the derivative of the concentrations. This occurs because the carriers are diffusing from areas of high concentrations to areas of low concentrations. For example, if the derivative of pwith respect to x is positive, then the concentration of holes is growing as you move towards the +x direction. Diffusion current will be the opposite of that, the holes will be diffusing in the -x direction to where there's a lower concentration of holes. If the derivative is negative, the opposite will occur. The concentration of holes is decreasing as you go from the -x to +x direction. Therefore, holes will diffuse to the +x direction where there's a lower concentration of holes. This is why the negative sign is needed in the equation for the hole diffusion current. The same goes for electrons, but in this case, the signs cancel for a positive derivative because the electrons, carrying -q, diffuse to the -x direction where there's less electrons. The sign remains if the derivative is negative, because electrons will be diffusing to the +xdirection carrying a -q charge. For these reasons it's not included in the equation for the electron diffusion current. source: http://www.ece.utep.edu/courses/ee3329/ee3329/Studyguide/ToC/Fundamentals/CAction/diffusion.html The difference between drift current and diffusion current is that drift current depends on the electric field applied: if there's no electric field, there's no drift current. Diffusion current occurs even though there isn't an electric field applied to the semiconductor. It does not have E as one of its parameters. The constants it does depend on are Dp and Dn, and +q and -q, for holes and electrons respectively. The first constants are called the diffusion coefficients, a proportionality factor. We don't worry too much about these because they are constants. We do worry about the gradient of the concentration of p and/or n, though. But, since we are talking about a one dimensional situation when we are solving for current densities, we only worry about the gradient (or derivative) with respect to the x-plane. The other difference between drift current and diffusion current, is that the direction of the diffusion current depends on the change in the carrier concentrations, not the concentrations themselves. In the equation, the signs are reversed as we are used to seeing them. We usually assign a +q to holes and -q to electrons. In the case of diffusion current, they are reversed to be opposite of the derivative of the concentrations. This occurs because the carriers are diffusing from areas of high concentrations to areas of low concentrations. For example, if the derivative of pwith respect to x is positive, then the concentration of holes is growing as you move towards the +x direction. Diffusion current will be the opposite of that, the holes will be diffusing in the -x direction to where there's a lower concentration of holes. If the derivative is negative, the opposite will occur. The concentration of holes is decreasing as you go from the -x to +x direction. Therefore, holes will diffuse to the +x direction where there's a lower concentration of holes. This is why the negative sign is needed in the equation for the hole diffusion current. The same goes for electrons, but in this case, the signs cancel for a positive derivative because the electrons, carrying -q, diffuse to the -x direction where there's less electrons. The sign remains if the derivative is negative, because electrons will be diffusing to the +xdirection carrying a -q charge. For these reasons it's not included in the equation for the electron diffusion current. source: http://www.ece.utep.edu/courses/ee3329/ee3329/Studyguide/ToC/Fundamentals/CAction/diffusion.html


Why is the current in diodes only due to diffusion and not influenced by electric field of batteries?

In diodes there are two types of current namely diffusion and drift current. Former one is due to concentration gradient of majority carriers (hole in p side n electron in n-side). Due to this difference of concentration of carriers majority carrier start to diffuse in other side. The amount of diffusion is just depends on concentration. Contrast to this, drift current which is very small in compare to diffusion current depends on the applied voltage across the diode. Since total current is mainly due to diffusion in forward biased hence it is not too much effected by battery's electric field. I dint know that batteries have electric field. INTERESTING.


What relation between electric current and drift velocity?

The drift velocity of free electrons in a conductor is directly proportional to the magnitude of the electric current flowing through the conductor. This means that as the current increases, the drift velocity of the electrons also increases. The relationship is described by the equation I = nAvq, where I is the current, n is the number density of charge carriers, A is the cross-sectional area of the conductor, v is the drift velocity, and q is the charge of the charge carrier.


What is meant by drift current in diode?

when ever the external voltage is given the movement of charge carriers produce a current i.e drift current


What is the process by which beach sediment moves down the beach with the current?

the process in which beach sediment move down a beach with the current


What is the name of a weak current?

drift


What is zero drift current?

Zero drift current refers to the small amount of electrical current that flows through an operational amplifier when the input voltage is zero. This current can cause errors in precision measurements because it can create an offset in the output voltage of the amplifier. Minimizing zero drift current is important in applications where accurate and stable voltage measurements are required.