How does reverse bias affect leakage current in a diode?

In summary, the leakage current in a reverse biased diode is caused by thermally generated electron-hole pairs. The electrons move through the diode and encounter holes due to p-type doping. However, due to low electron mobility, most of the electrons recombine with the abundant holes and only a few make it to the junction barrier. This also depends on the doping level and whether the semiconductor material is n-type, p-type, or intrinsic.
  • #1
Danish_Khatri
26
0
My question is related to the leakage current occurring in a diode when connected in reverse bias mode. When the diode is forward biased, the source voltage first neutralizes the barrier potential and then the flow of current occurs. However, I am not able to understand how the current due minority charges flow through a diode when it is reerse bias.
I would be very grateful if there is someone who can help me with this confusion.
 
Engineering news on Phys.org
  • #2
In reverse, electron-hole pairs are being thermally generated just as in the forward case. For every electron removed from its parent atom, a hole is generated as well. The electrons move when reverse biased, and they encounter holes due to p-type doping. The thermally generated electrons & holes are equal in number, but doping a semiconductor with p-type impurites, i.e. acceptors, results in low electron mobility. The electrons recombine with the abundant holes and few make it to the junction barrier. Likewise, on the n-side, an excess of electrons occur due to doping, and holes have low mobility.

It's all about mobility of e- & h+ which varies with doping level and whether the semiconductor material is n-type, p-type, or intrinsic.

Claude
 
Last edited:

What is leakage current in diode?

Leakage current in diode refers to the small amount of current that flows through a diode even when it is reverse biased. This current is typically very small, on the order of microamps or even nanoamps, and can be caused by imperfections in the diode's construction.

What causes leakage current in diode?

Leakage current in diode can be caused by a variety of factors, such as defects in the crystal structure of the diode, impurities in the materials used, or temperature fluctuations. These imperfections can create small paths for current to flow through, even when the diode is supposed to be blocking the flow of current.

Why is leakage current in diode important?

Leakage current in diode is an important consideration in electronic circuits because it can affect the overall performance and efficiency of the circuit. If the leakage current is too high, it can cause unwanted power dissipation and potentially damage the diode or other components in the circuit.

How can leakage current in diode be reduced?

Leakage current in diode can be reduced by using high-quality diodes with low defect levels and using proper circuit design techniques. Additionally, keeping the diode at a lower temperature can also help reduce leakage current, as it is often influenced by temperature fluctuations.

Can leakage current in diode be completely eliminated?

No, leakage current in diode cannot be completely eliminated. However, it can be minimized to a very low level through careful selection of diodes and proper circuit design. In some specialized applications, such as high precision measurement circuits, additional techniques may be used to compensate for the remaining leakage current.

Similar threads

  • Electrical Engineering
Replies
7
Views
2K
Replies
23
Views
2K
  • Electrical Engineering
Replies
8
Views
2K
Replies
42
Views
2K
  • Electrical Engineering
Replies
6
Views
2K
Replies
5
Views
2K
  • Electrical Engineering
Replies
16
Views
6K
Replies
1
Views
780
  • Electrical Engineering
Replies
1
Views
3K
Back
Top