With all the variety of modern element base of electronics must not forget that it is based on very simple things, one of which is a semiconductor diode.
It should immediately be noted that at first glance it is a simple element.In fact, its use allows to solve a variety of tasks in the field of electronics and electrical engineering.The technology of manufacture of such devices is not particularly complicated.
diode consists of two different-type conductivity material called n-regions and p-type conductivity conductivity.If we consider the principle of the semiconductor diode, you have to delve into concepts such as a pn junction, electron emission, diffusion, and other similar physical effects.Therefore, leaving the discussion of these questions for another case, we use the comparison.Compare the semiconductor diode may be a valve.Due to its structure, consisting of two different type conductivity material, such a device exists unilateral conductivity, which means that an electric current can flow through it in one direction only.The same thing happens when the valve is used - water or air may pass in one direction only.Example - bicycle camera: to air flows and back - no.
seemingly very simple effect - one-way conductivity, but gives a lot of opportunities to use it in practical use.In particular, a semiconductor diode converts the AC to DC.There is a class of products called rectifier diodes.
They work just like a valve.If the polarity of the voltage applied to the article, corresponds to the desired, i.e.When a plus voltage is applied to the positive side of the device, and negative to negative, then through the electric current, if not, nothing happens.
It is because of the effect described AC voltage is converted into a permanent one.The input circuit is fed AC voltage, but the voltage across the semiconductor passes only the correct polarity.As a result, we obtain the output voltage of only one polarity, while pulsing, i.e.changing amplitude.
This is not the only option for the use of semiconductor devices.At the pn junction, which is the basis of the diode, there are other properties, many of which are defined specifically in its manufacture.These characteristics are the basis for other, for the various device classes.This zener diodes high-frequency and pulse, varicaps, photodiodes, LEDs, etc.But they are all based on the properties of the pn junction.
However, there is a whole class of devices called "semiconductor diode Gunn" not related to the formation of such a transition.Their work is based on the so-called Gunn effect.It is caused by a whole set of complex phenomena occurring in the semiconductor crystal under certain external influences.As a result of these processes, the current flowing through the crystal changes its oscillations occur.That is to be generated and used such devices.Use them usually in the microwave technology as a source of vibrations.
Diodes are an integral part of any electronic device.They are used for separating and converting a voltage stabilization, filtering noise;easier to list the cases where they do not apply.For them, there are different types of body, designed for the different currents and voltages and installed both in the input and output circuits in electronic devices.Diode - this is probably one of the most common semiconductor devices.
Now you know what a semiconductor diode, and what are the options for its use.
