Photo Diodes
The PhotoDiodes can be Categorized as p-n Photodiodes,p-i-n Photodiodes and Avalanche Photodiodes.
The Brief Explanation about these three are given below
p-n Photodiodes
It depends upon the photo generated charged carriers for their operation. A photodiode is a p-n junction whose current in reverse bias increases when the material absorbs photons. Since an electric field can only support in the depletion region of the p-n junction, photocarriers are desirable to generate in this region.
So it is required to increase the length of depletion region for fast response.
p-i-n Photodiodes
As the name implies, these photodiodes consist of an undoped intrinsic layer between two highly doped p-n junctions. It gives better performance than the common photodiodes.
A high electric field is present in the depletion region of this photodiode causing newly generated charged carriers to separate and be collected across the reverse-biased junction. This leads to the flow of electric current in the external circuit.
where Ec is the energy of the covalent band and Ev is the energy of the valence band.
Avalanche Photodiodes
In the case of p-n photodiodes and p-i-n photodiodes, the output photocurrent is very small because of the very limited gain. To provide a large gain, the avalanche photodiode is used. The reverse bias is applied to the photodiode is closer to the breakdown value.
Photodetector
A photo is nothing but light. A detector is nothing but a device that detects something. Therefore, we can directly conclude that a photodetector can be defined as a device that is used to detect light radiations by absorption. In this Article, We will be going through Photodetector, We will start our Article with What is Photodetector?, Then we will go through its brief Working, then we will go through its properties and go through all the types, At last, we will conclude our Article with Advantages, Disadvantages and Some FAQs.
Table of Content
- What is PhotoDetectors ?
- Working of PhotoDetector
- Classes of PhotoDetector
- Photodetector Properties
- Types of PhotoDetector
- Comparison Between Photodetector and Photodiode
- Applications of Photodetector