Understanding the Advantages & Applications of PN Junction Diodes

A diode is a two-terminal electronic component that has high electrical resistance on one end and low electrical resistance on the other end. As a result, this widely used electronic component conducts electricity in one direction. 

Early diodes have two electrodes: cathode and anode. The cathode is a negatively charged electrode, while the anode is a positively charged one. These two electrodes were fixed on both sides of vacuum glass or metal tubes. Those early diodes were used as rectifiers and detectors in the electronic circuits of radio and television receivers.

However, modern diodes are made up of semiconductor materials and are used to perform several critical functions apart from controlling the electrical current flow. 

When exploring the concept of diodes, you’ll most likely come across the term “PN junction diodes,”  which are also the most popularly used didoes in electronic circuits today. Read on to get a better understanding of applications of PN junction diodes and how they work.

What Are PN Junction Diodes?

Diodes are mainly used to protect electronic circuits by normalizing voltage fluctuations and transforming Alternating Current (AC) into Direct Current (DC), a process known as rectification. The most common type of diode is a PN junction diode, also known as a rectifier diode. 

The PN junction diode has two layers of semiconductors: P-type and N-type. A P-type semiconductor is made by adding trivalent impurities such as Boron (B), Aluminium (Al), and Indium (In) to a semiconductor made up of silicon or germanium. N-type semiconductors are made by adding donor impurities like Phosphorus (P), Arsenic (As), and Antimony (Sb) to a semiconductor.

At the intersection of P-type and N-type semiconductor materials, a depletion area is formed as a positive and negative charge region on each side of the PN junction diode. 


The PN junction diode functions in two ways: forward-biased and reverse-biased. These two functions determine their usability in different applications. 

The positive voltage terminal supplies power to P-type semiconductor material, while N-type semiconductor material is connected to the negative voltage terminal in a forward-biased PN junction diode. Therefore, the built-in and applied electric fields are in opposing directions in a forward-biased PN junction diode. 

When the P-type and N-type semiconductors are connected to the negative and positive voltage terminals, respectively, The PN junction diode turns into a reverse-biased one. In this case, the applied and built-in electric fields are in the same direction.

Here are some of the standard applications of PN junction diodes.

  • Rectifiers
  • Voltage amplifiers
  • Clipper and clamper circuits.
  • Integrator or differentiator circuits used with Operational Amplifier (OP-AMP)
  • Voltage regulators
  • Light-emitting Diode (LED)

Advantages of PN Junction Diodes

  • An efficient rectifier
  • It suppresses voltage spikes and protects electronic components.
  • Faster operation as it does not require any startup time.
  • One of the cheapest diode types.
  • It consumes lesser power.
  • Small-sized yet lightweight.
  • It has longer life.

Diodes, made up of semiconductor materials like silicon and powered by electricity, are driving today’s technology-driven world. They also play a more significant role in fuelling the global renewable energy trend, as diodes are a crucial component in solar cells. Similarly, the rising optical communications and 3D sensing technologies benefit significantly from diodes. 

To learn more about the applications of PN junction diodes or inquire about our available inventory, please contact our expert team at Solid State Inc. today.