What is LED how pn junction diode can work as LED?
What is LED how pn junction diode can work as LED?
LED technology: how a LED works The LED is a specialised form of PN junction that uses a compound junction. The light emitting diode emits light when it is forward biased. When a voltage is applied across the junction to make it forward biased, current flows as in the case of any PN junction.
What is the working principle of diode?
The most common function of a diode is to allow an electric current to pass in one direction (called the diode’s forward direction), while blocking it in the opposite direction (the reverse direction). As such, the diode can be viewed as an electronic version of a check valve.
How do you explain the working of LED by using the energy band diagram in forward biasing?
When Light Emitting Diode (LED) is forward biased, free electrons in the conduction band recombines with the holes in the valence band and releases energy in the form of light.
What is the difference between pn junction diode and LED?
The LED emits light. The PN junction diode cannot emit light. In PN junction diode all energy converted into a heat. …
What do you understand by PN junction diode?
A p-n junction diode is a basic semiconductor device that controls the flow of electric current in a circuit. It has a positive (p) side and a negative (n) side created by adding impurities to each side of a silicon semiconductor. The symbol for a p-n junction diode is a triangle pointing to a line.
Why do LEDs only work in one direction?
A diode is a device that allows current to flow in only one direction. When a so-called forward bias (a voltage in the “forward” direction) is applied, current flows freely through the device. When the voltage is applied in the opposite direction (called a reverse bias), no current flows.
What is LCD and how it works?
A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directly, instead using a backlight or reflector to produce images in color or monochrome.
