Diode: Definition, Symbol, and Types

What is a Diode? A diode is defined as a semiconductor device with two terminals that conducts current in one direction only (if operated within a specified voltage level) A diode only blocks current in the reverse direction while the reverse voltage is within a limited range otherwise reverse barrier breaks and the voltage at … Read more

What is Photodiode? Working Construction Characteristic Applications

What is Photodiode? The photodiode is a kind of pn junction semiconductor diode which works with the intensity of light falling on it at the reverse biased condition. Working Principle of Photodiode When a diode is in reverse biased condition, there would be a reverse saturation current flowing through it from positive to the negative … Read more

Vacuum Diode History Working Principle and Types of Vacuum Diode

History of Vacuum Diode In November 16, 1904 first vacuum diode was invented by Sir John Ambrose Fleming and it is also called the Fleming valve, the first thermionic valve. In those days there was no existence of p-n junction in electronics field. A conceptual figure of vacuum diode is shown below. How Does Vacuum … Read more

Power Diodes

Diodes are the simplest semiconductor device having only two layers, two terminals and one junction. The ordinary signal diodes have a junction formed by p type semiconductor and n type semiconductor, the lead joining p type is called anode and the other side lead joining the n type is called cathode. The figure below depicts … Read more

GUNN Diode

Gunn diode is a passive semiconductor device with two terminals, which composes of only an n-doped semiconductor material, unlike other diodes which consist of a p-n junction. Gunn diodes can be made from the materials which consist of multiple, initially-empty, closely-spaced energy valleys in their conduction band like Gallium Arsenide (GaAs), Indium Phosphide (InP), Gallium … Read more

Reverse Recovery Time of Diode

A diode when functioning in its forward bias condition has its depletion region shrinked to almost nothing. That is, the external supply voltage applied will be used by the device to overcome the barrier potential which gets imposed on it due to the presence of immobile charge carriers in its depletion region. Now, imagine that … Read more

Diode Testing

It is well known that a diode is expected to operate as a unidirectional device (i.e. only permit current flow in one direction). These are expected to offer very low resistance for the flow of current under the forward biased condition and a very high resistance under the reverse bias condition. This important property of the diode … Read more

Varactor Diode

Varactor Diode is a reverse biased p-n junction diode, whose capacitance can be varied electrically. As a result these diodes are also referred to as varicaps, tuning diodes, voltage variable capacitor diodes, parametric diodes and variable capacitor diodes. It is well known that the operation of the p-n junction depends on the bias applied which … Read more

Laser Diode

Laser diodes are the semiconductor lasers which generate highly intense coherent beam of light. These were developed by Robert N. Hall in early 1960s and are also referred to as injection lasers. It is well known that an incident photon can interact with the atom to release a photon which will be identical to the … Read more

Ideal Diode and Characteristics of Ideal Diode

An ideal diode means a perfect diode which has all properties in their perfect sense without any flaws. Usually, a diode operates either in forward or reverse biased condition. The characteristics which are expected to be exhibited by the ideal diode can be analyzed separately for these two modes of operation. Characteristics of Ideal Diode … Read more