7.2. Correction of Current Formula

jumping into this one, and it may create abundant availability of the electrons and contributing significantly to this collector current. In other words, based on this voltage the electrons are getting injected into the base region, and they are nicely collected by the collector terminal by the virtue of this strong reverse bias voltage.

This chunk discusses how the collector current in a BJT (Bipolar Junction Transistor) is influenced by the availability of electrons. When a voltage is applied, it allows electrons to flow into the base region of the transistor. As these electrons accumulate, they are pulled into the collector terminal due to a strong reverse bias voltage, which creates a significant collector current. Essentially, the application of this voltage plays a crucial role in controlling the movement of electrons, enabling the transistor to function properly.

Think of it like water flowing through a pipe. When pressure (voltage) is applied, it pushes water (electrons) into a reservoir (the base region). The reservoir collects water, and if a strong drainage system (reverse bias) is in place, it effectively pulls more water from the reservoir, increasing the water flow (collector current).

So, if these two junctions are remaining isolated, we cannot get BJT operation, it will be rather working as two back to back diodes. And this will be getting converted only when these two junctions are moving close to each other in the near vicinity.

This part explains that if the two junctions of a BJT (the emitter-base junction and the collector-base junction) are not close enough, the BJT will not function properly. Instead, it would behave like two back-to-back diodes. For the BJT to operate effectively, the junctions need to be in close proximity to one another, allowing for the necessary interaction between the carrier distributions across both junctions, which is crucial for the functionality of the transistor.

Imagine two magnets that need to be close together to attract each other. If they are too far apart, they can't affect each other, which is similar to how the junctions in a BJT must be close enough to influence the electron flow effectively.

if the electrons are having profile like this and if this junction it is coming in the near vicinity. So, instead of having an exponential fall of the minority carrier rather it will be having going to drop to 0, because of the reverse bias.

Here, the text describes how the behavior of minority carriers in a BJT changes when the junctions are close and under reverse bias. Normally, in a typical situation, the minority carrier concentration decreases exponentially away from the junction. However, when a junction is in reverse bias and close to another junction, the concentration can drop sharply to zero, indicating that fewer carriers are available to contribute to current flow at that point due to the reverse bias effect.

Think of it as a crowded hallway where people (electrons) are trying to move to one side. In normal conditions, the number of people decreases the further you go down the hallway (exponential fall). However, if a strong barrier (reverse bias) is put up closer to the entrance, it prevents most people from getting in, causing an abrupt end to the flow of people in that direction (zero concentration).

This is where we are talking about the current particularly current carried by electron. I like to mention here a small correction; please make a note of that... So, expression of current carried by electron equals to ‧n po ( ) , and as I say that if I consider x = 0. So, this part it becomes 1 and hence this is rest of the things it is giving the current flow are carried by electron.

In this chunk, a correction to the current formula is discussed, where the contribution of the electron current needs to be noted correctly. The expression for the current carried by electrons is defined, highlighting that when evaluating at a specific position (x = 0), the calculations simplify, signaling that this position contributes significantly to the electron current flow. It’s important to understand that the numerical values and constants in the formula need to be correctly referenced to ensure accurate calculations.

Consider a recipe where you add ingredients in the wrong amounts. Just like adjusting the ingredients can affect the taste of the dish (current flow), making the right corrections in the formula ensures that you get the correct result in calculating electron current.

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