Semiconductor Diode


  • The semiconductor devices are known to display properties of partial electrical conductivity. They neither classify into mainstream conductors nor insulators and thus they permit partial conductivity in the process.

  • These semiconductor diodes are further classified into two-terminal and threeterminal devices. Various forms of diodes fall under the category of two-terminal devices.

  • The semiconductor diodes are also made of a single p-n junction and have metallic contacts on both the extreme ends to enable the application of external voltage into it. These diodes have the ability to conduct electricity in any one particular direction.

What are semiconductor diodes?

Semiconductor diodes are classified as the does that are composed of various semiconducting materials.

The negatively charged cathodes present in these diodes are accumulated with a vast number of electrons and this cathode is present adjacent to the anode that carries an unrestrained amount of positive charge from the holes.

These semiconductor diodes are formed as a result of a P-N junction and this junction has metallic contact on the extreme ends of it. These metallic contacts at the ends of the junction help in applying external voltage into the diode. These diodes have the intrinsic characteristic of conducting electricity in a particular single direction.

Figure 1: Symbol of p-n junction diode

The p-n junction diode and the Zener diode are most prominent forms of semiconductor diodes. The junction that is formed between the cathode and the anode in a particular semiconductor helps in the forming a region of depletion, this region is void of any kind of electrons and holes.

Positive voltages in a semiconductor diode exist at the site of the anode and the depletion region gradually decreases in size thereby enabling of flow fo current through a semiconductor diode.

Semiconductor diodes: types

Semiconductor diodes are further classified under two significant sections that are dependent on the connection used in the semiconductor. One of these two classifications is semiconductor diode forwards bias(circuitglobe 2022).

A battery is known to have two distinct terminals, one is the positive terminal and the other is a negative terminal. Hence, when the N and P end of a semiconductor is found to be fixed with the negative and positive side of the battery, respectively, the diode is known to be a semiconductor diode of forward bias the negative end of the diode will fend off free electrons towards the front end of the diode and the P end of the semiconductor with push the holes and these two units will meet at the junction (electricaltechnology 2022).

However, the free electrons that are coming out of the battery will tend to penetrate the N region and the electrons that are abandoning the P end will enable the movement of current.

Figure 2: Construction of Semiconductor diode

The other type is semiconductor diode reverse bias, in this diode the Negative side of the diode is affixed with the positive terminal of the battery. Electrons from the N end of the battery will move towards the positive end (physics-and-radio-electronics 2022).

In this setup, there is a clog of current since the holes and electrons never meet at a certain junction. Therefore, the majority of the current is unable to flow in the reverse bias.

Semiconductor diode: characteristics

There are certain significant features associated with the forward bias and reverse bias. In the case of raising the forward bias, a rise of current is observed (etechnog 2022). The current rises to a stable voltage which is also termed knee voltage occurs in a linear manner. After attainment of this voltage, however, the current does not adhere to the linear motion.

Figure 3: Semiconductor diode forward bias

The reverse current however does not depend on the reverse current. In this case, the current however depends on the temperature at the junction.

Semiconductor diode: Applications

There are multiple applications of semiconductor diode in day-to-day life. These diodes are used in the mixing signals and also control the size of these signals. As opined by Zareian et al. (2018), the light-emitting diode is used for the emission of a spectrum of infrared light.

Photodiode as used a photo detectors. According to Riza Putra et al. (2021), rectifier diodes are used for better efficiency of alternating current. The diodes are also used for the isolation of signals from the whole supply. Zener diodes are used in stabilizing current and voltage in electric systems.


Semiconductor diodes are widely used in multiple pieces of electronic equipment emphasizing their efficiency in commercial and industrial pieces of equipment. These diodes are primarily of two types that are classified based o forward bias and reverse bias. These diodes are mostly made up of silicon and germanium which are excellent semiconducting materials in general. Zener diode and p-n junction diodes are prime examples of semiconductor diodes. These diodes are mostly formed by joining up p and n-type semiconducting material that helps in the formation of p-n junctions. A semiconductor diode contains only one p-n junction diode.


Q1. What materials are used for making a semiconductor diode?

Ans: These diodes are made of semiconducting materials. These diodes are mostly made of silicon and germanium.

Q2. What are the different kinds of semiconductor diodes?

Ans: There are multiple kinds of semiconductor diodes. Most prominent of them are rectifier diode, Zener diode, Light-emitting diode, Peltier and Thermal diode and point contact. Besides this, there are various other kinds of diodes.

Q3. What are the most prominent applications of semiconductor diodes?

Ans: The semiconductor diodes are used for mixing various kinds of signals. However, these are used to separate signals from a whole supply. Semiconductor diodes are used for rectification of voltage and convert into direct current or alternate current. These diodes are also helpful in rectifying alternating current

Q4. What is the use of Zener diode and Gunn diode?

Ans: Zener diode is used for stabilizing the current and voltage coursing through various types of electrical equipment. The Gunn diodes are also used in electronic devices of high frequency.


Simply Easy Learning

Updated on: 13-Oct-2022

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