The first device capable of letting electric current pass in one direction while blocking it in the other, was discovered in 1874 by Karl Ferdinand Braun with a galena crystal. At the beginning of the 20th century, copper oxide or selenium rectifiers were used to convert alternating current to direct current. This use applied through most of the century to charging batteries. In 1901, Peter Cooper Hewitt invented the mercury vapor rectifier, which was used for power applications until the 1970s. At the same time, seeking to improve the detection of radio waves, John Fleming developed the first electron tube (the vacuum diode), whose heated cathode emits electrons that the anode can pick up, while the opposite is not possible. The germanium or silicon semiconductor diode replaced vacuum tubes after World War II. The development of semiconductors has led to the creation of many varieties of diodes, exploiting the characteristics of the P-N junction, or, in the case of light-emitting diodes, the ancillary properties of the material.
Diode - the simplest semiconductor device
Despite its simple operation, the diode is a very useful component. Its primary function is to pass current in one direction only, while blocking it in the opposite direction. This phenomenon is called barrier polarization. Diodes are divided into different types, from the simplest to the most complicated devices. Advanced diodes work on the principle of non-linear current-voltage characteristics, which means that they can do more than just control the flow of current. It is also worth remembering that semiconductor diodes conduct electrical current when you exceed a threshold voltage in the direction of conductivity. Only temperature can affect the voltage drop of a diode, so this effect is used to measure it. In our offer we have prepared many diodes, which can meet the requirements of both professionals and amateurs. If in doubt, please contact our technical department, who will happily advise you on choosing the right product.
Different types of diodes
There are several types of diodes for different applications.
- Light-emitting Diode (LED) light: This is one of the most popular type of diodes. This diode allows the transfer of electric current between the electrodes which produces light. The color of the light depends on the band gap of the semiconductor.
- Avalanche Diode: This type of diode operates in reverse bias and applies avalanche effect for its operation. The avalanche diode is generally used for photodetection, where high levels of sensitivity can be achieved by the avalanche process.
- Laser Diode: This type of diode is different from the LED type because it produces coherent light. These diodes are used in DVD and CD players and laser pointers.
- Schottky Diodes: These diodes have lower forward voltage drop compared to ordinary silicon diodes with PN junction. The voltage drop can be somewhere between 0.15 and 0.4 volts at low currents, compared to 0.6 volts for a silicon diode.
- Zener Diode: This type of diode provides a stable reference voltage, therefore is very useful and in large quantities. The diode works in reverse bias and fails on the arrival of a certain voltage.