Diffusion Current :

The carrier currents are also due to concentration gradients in the doped material which lead to diffusion of carriers from high concentration region to low concentration region. A concentration gradient exists if either the number of holes or electrons is greater in one region as compared to the rest of the region. When a concentration gradient of carriers exists in a material, the charge carriers tend to move from the region of high concentration to the region of lower concentration. The process is called the diffusion and the current due to this process is called the diffusion current. Let us assume that at reference plane x, the density of holes is p per m3. Let the carriers have a mean free path of Ax and mean free time of at between collisions.

Total Current in a semiconductor

It is possible that a potential gradient and a concentration gradient may exist within semiconductor. In such a case, the total current is the sum of drift current due to potential gradient and the diffusion current due to charge carrier concentration gradient.

Posted Date: 2/8/2013 2:47:35 AM | Location : United States

Ask an Expert

Related Discussions:- Diffusion current, Assignment Help, Ask Question on Diffusion current, Get Answer, Expert's Help, Diffusion current Discussions

Write discussion on Diffusion current
Your posts are moderated

Write your message here..

Related Questions

Image retreval and face recognization technique, block diagram of eigen fac... block diagram of eigen face,Viola & Jones Method,Bio-ID,RWTH-i6 Groups of People Database

Explain in detail the operation of 8255 in mode 1, Explain in detail the op... Explain in detail the operation of 8255 in mode1 taking suitable example. In mode1, Ports A and B are programmed as input or output ports and Port C is used for handshaking.

2365 - 305 task a, List four sources of information which are essential to ... List four sources of information which are essential to the designer of this electrical installation.

Calculate the voltages that will be indicated by instrument, An electromech... An electromechanical voltmeter with internal resistance of 1 k and an electronic voltmeter with internal resistance of 10 M are used separately to measure the potential differenc

Find the new synchronous speed, Q. A wye-connected, three-phase, 50-Hz, six... Q. A wye-connected, three-phase, 50-Hz, six-pole synchronous alternator develops a voltage of 1000 V rms between the lines when the rotor dc field current is 3A. If this alternator

Stator voltage control methods - motor control , Stator Voltage Control Met... Stator Voltage Control Methods By  controlling  the applied voltage  the speed  of an  induction motor  can be  controlled. Since  the output  torque of 3-? induction motor  i

Bridge Rectifier:, program for matlab program for matlab

Discuss dma operation in brief, Discuss DMA operation in brief. The fun... Discuss DMA operation in brief. The fundamental idea of DMA is to transfer blocks of data directly among memory and peripherals. The data don't suffer the microprocessor but th

Evaluate the damping ratio for the gain, A feedback control system with the... A feedback control system with the configuration of Figure has the following parameters: K p = 0.5 V/rad, K a = 100 V/V, K m = 2.7 × 10 -4 N·m/V, J = 1.5 × 10 -5 kg·m 2 , and

Explain the advantage of synchronous counters, Explain the Advantage of Syn... Explain the Advantage of Synchronous Counters? The most significant advantage of synchronous counters is that there is no cumulative time delay because all flip-flops are trigg