- red light emitting diode - - - - - - The secret of the diodes.
light emitting diode ( Red light emitting diode) As a new lighting source is began to popular in recent years, it is one of the biggest features high luminous efficiency, can greatly save precious energy for us. As we know, generally light-emitting diodes (leds) are small, and there are multiple colors, how can such a little thing is bright light? Let's go and have a look in current light-emitting diodes (leds secret!
when a p-type semiconductor with a piece of n-type semiconductor, forming a p-n junction, the pn junction is the vast majority of semiconductor devices one of the most basic structure. And ends when the p-n junction, do a good job of electrode and lead to pin and then packaging, has formed a diode. Next, we need to do is to make it shine.
when p cavity to n area diffusion, and diffusion of n to p electronic area, equivalent to the applied electric field for n area into the electronic injection hole, and to give p area. Injection hole n area quickly and electronic composite radiation photon, electron injection p were quickly and hole compound radiation photons, so the p-n junction in the electric field under the action of light. When the voltage is very small, the amount of injected carrier also very small, only the light invisible to the naked eye. Only when the applied voltage is close to or more than the built-in electric field voltage will inject carrier in large quantities, so we can see the bright light diode.