Metal-semiconductor Metal Photodiodes

What is Photodetector ?

Photo means light. A detector is a device that detects something. So, a photodetector can be defined as a device that is used to detect light radiations by absorption. It converts light pulses(or radiations) energy into electrical signals in the form of current & voltage. Sometimes, it is also called photosensors. As the name implies, it detects incident photons or radiations by absorbing the incident lights. The principle behind this process is known as photodetections....

Working of Photodetector

The basic principle of the photodetector is that when an incident light or radiation falls on the surface of detector and get absorbed, it converts it into electrical signals....

Classes of PhotodetectorClassification of Photodetector

Based on their uses, there are two principal classes of photodetectors commonly which are common in used:...

Properties of Photodetector

There are several properties of photodetector describes as follow:...

Types of Photodetector

Many types of photodetectors are classified based on the mechanism of the absorption of photons, photoelectric effect, temperature effect and other emission effects....

Photo Conductors

When photons are absorbed by a semiconductor material when light falls on the surface of the material it leads to the generation of mobile charged carriers (electron-hole pairs). There is a rise in the conductivity of the material in proportion to the amount of photon flux. An electric field due to an external voltage source causes the transportation of electrons and holes which results in a measurable electric current in the circuit....

Photo Diodes

The PhotoDiodes can be Categorized as p-n Photodiodes,p-i-n Photodiodes and Avalanche Photodiodes....

Metal-semiconductor Metal Photodiodes

It is also called Schottky-barrier photodiodes. These photodiodes are made from metal and semiconductor heterojunction. A thin semi-transparent metal film is used in place of the p-type or n-type layer in the p-n junction photodiode. The thin film is mostly made of a metal-semiconductor alloy that acts like a metal. The Schottky barrier photodiodes have fast response and large operating bandwidth....

PhotoTransistors

Phototransistor is Photodiode + transistor. It is a semiconductor device having three terminals. It also used to convert incident light into photocurrent. The incident light( or radiation) falls on the base terminal and after that, it is converted into photocurrent which flows through collector and emitter. The transistor is used with photodiode because the current produced by the photodiode is low, that is why transistor is used to amplify the current....

PhotoTubes

In this device, it emits negative charge carriers i.e, electrons from a photosensitive negative charged cathode when it stike by visible or UV radiations. Electrons e– flow through a vacuum to an anode to produce current which is proportional to radiation intensity....

PhotoMultiplier Tube

It is very sensitive device in which electrons emitted from photosensitive cathode strike a second surface called as dynode. Dynode is positive +ve with respect to the original cathode. Electrons are this accelerated and can knock out more than one electron from the dynode....

Charge Coupled Device

A charge-coupled device (CCD) is termed as most sensitive photodetectors. A charge coupled device is a device for the movement of electrical charge within the device to an area where charge can be manipulated. It is an IC(integrated circuit) having one array of linked, or coupled, capacitors. With the external circuit connection, every capacitor transfer their charge to the neighbor capacitors. It is majorly used in the image processing technology....

Comparison Between Photodetector and Photodiode

Photodetector Photodiode Photodetector is a device which sense light radiation. Photodiode is a photodetector but it also detects the light intensity. It is used to detect light radiations. It is light sensitive diode made of semiconductor. It does not have amplifier to detect the light. Photodiodes have amplifiers connected in them for the detection of light having low level of intensity. It is made of compound semiconductor having 0.73eV band gap. It is made of p-type. n-type, or p-n type of semiconductor junctions. Sometimes, It also have intrinsic junction. Its response time is slow. Its response time is fast....

Advantages and Disadvantages of Photodetector

Given Below are Advantages and Disadvantages of PhotoDetector :...

Applications of Photodetector

These are the following applications of photodetectors:...

Conclusion

In this article, we learned and got the detailed knowledge about photodetector. This article categorised based on the topics including working, classes, types, characteristics , merits and demerits of photodetector....

FAQs on Photodetector

What is Photosensor?...