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What else can I help you with?
Why two diode join cant act as transistor?
No, it is not possible because in transistor the depletion layers formed in Emitter-Base Junction & Collector-Base Junction are penetrable by both current carriers but in this case of two diodes; the formed depletion region are not penetrable for current carriers (hole &electron). Also, a transistor works only because the base layer is very thin. You won't get that thin layer between emitter and collector just by connecting two diodes together. This thin base layer places the Emitter and Collector in very close proximity to each other. This allows majority carriers from the emitter to diffuse as minority carriers through the base into the depletion region of the base-collector junction, where the strong electric field collects them. In other words the emitter/base current flow draws some of the barrier charge away from the collector/base junction and allows collector/emitter current to flow across the base using minority carriers. So transistor action is not possible. But we can make transistor by connecting two diodes and two dependent current sources i.e. Ebers-Moll model of transistor. This is true only when you want to make the transistor act like a on/off switch, but you cannot make this setup of diodes to act like an amplifier. Whereas the transistor also acts as an amplifier too A transistor can act as: (1) on/off switch (2) amplifier. Diode is made up of two layers and one junction. Transistor is made up of three layers and two junctions.
Why transistor have 4 wire?
The transistor is a three layer (or two junction) device, emitter, base, and collector (or other designations for variations such as FET's). Each layer is connected to a terminal. Three layers - three terminals.
What causes the depletion layer?
Depletion layer The area in a P-N junction that is free of (i.e., depleted of) current carriers.
How do you control PN-junction?
When a pn junction is direct polarized, the height of the depletion layer is reduced and majority charge carriers now have sufficient energy to cross the junction and when it is revers polarized the height of the depletion layer is increased and the number of majority charge with sufficient energy to cross the junction is cut sharply.
What is the depletion layer in a semi conductor?
in correct sense it is not the layer but the region around the metallurgical junction which is depleted of charge carriers .in this region an internal electric field exist which counter balance the diffusion of electron and hole around the junction . basically the main reason for the formation of depletion region is the concentration gradient across metallurgical junction of p-n semiconductor.
How built-in potential barrier is formed in an open circuited P-N junction?
depletion layer surrounding the junction where electrons from N side have fallen into holes from P side.
What is the thickness of the depletion layer in a semiconductor?
The thickness of the depletion region or depletion layer (and there are other terms) varies as the design of the semiconductor. The layers in a semiconductor are "grown" (usually by deposition), and this can be controlled. The typical depletion region thickness in an "average" junction diode is about a micron, or 10-6 meters. Junction "construction" presents major engineering considerations to those who design and make semiconductors as there are many different kinds. A link is provided to the section on the width of depletion regions in the Wikipedia article on that topic.
Explain the formation of depletion layer in pn junction diode?
hey dear, in p-n junction p-type material has more positive charged called holes and n-side having e-in majority... when we apply negative biasing then negative terminal is connected to p terminal then holes are attracted by negative terminal and e's are attracted by positive terminals.....and minority carries are forced towards junction, then at junction electron and hole pair generation occurs. after this at junction charge is accumulated by attraction and junction is get wider by a small amount that is called as depletion layer...... now you can understand how depletion layer is created..
What pnp friendly means?
Since this is in the electronics section, I'll assume you mean a PNP transistor. PNP refers to the semiconductor layers used to make up the transistor. The P and N letters refer to positive and negative doping in the semiconductors, which changes the way electrons flow through the layers. This is a bipolar junction transistor (BJT), which can be thought of as a current amplifier. One P layer is called the emitter and the other is called the collector. The N layer is called the base. The emitter and collector are not usually interchangeable because they are made differently. When the voltage on the base is below the voltage on the emitter, usually by about 0.7 Volts, current flows from emitter to base. This allows a much larger current to flow from emitter to collector. This assumes the collector is at a lower voltage than the base, and is the usual connection. Similarly, there are NPN transistors.
Why the depletion layer becomes very thick when then pn junction diode is lightly doped?
When the pn junction is forward biased,the height of the potential barrier is reduced allowing more majority charge carriers ti flow across the junction and when it is reversed biased, the height of the potential barrier increases there b reducing the majority charge carrier that have sufficient energy to flow across the junction.
What effect of depletion layer by biasing?
on forward biasing width of the depletion layer decreases whereas on reverse biasing the width of depletion layer increases.
What is ment by early effect in transistor?
For a fixed value of Vbe,as Vce increases the reverse bias on the collector base junction increases,hence the width of the depletion layer increases.therefore base width decreases,so collector current increases. To minimise this effect base must be heavily doped than collector CONSEQUENCES: ->due to early effect collector current increases with increasing Vce,for a fixed value of Vbe. ->the base current do not change significantly Early effect=collector current * correction factor
