Question

how should Junction diode connected to a battery to keep it facing forward? ​

Answer 1

Answer:

 light-emitting diode or LED lights up when electrically biased in the forward direction. This effect is a form of electroluminescence. 

A LED is a special type of semiconductor diode. Charge-carriers are created by an electric current passing through the pn-junction, and release energy in the form of photons as they recombine. The wavelength of the light, and therefore its color, is dictated by the materials forming the pn junction, which elements doped the pure material. A normal diode, emits invisible far-infrared light, but the materials used for a LED have bandgap energies corresponding to near-infrared, visible or near-ultraviolet light.

Answer 2

Forward Biased PN Junction :

Explanation:

• A PN junction is alleged to be forward-biased once the p-type region of a junction is connected to the positive terminal of a voltage supply and therefore the n-type region is connected to the voltage source’s negative terminal.

• In this forward-biased condition, because of the attraction of the positive terminal of the supply, electrons that participated in chemical bond creation within the p-type material are attracted towards the terminal.

• As a result, the quantity of valency bonds is broken and the electrons area unit shifted towards the positive terminal. This leads to the electrons’ concentration within the crystal nearer to the terminal to extending, and these electrons recombine with holes here.

• In this method, the quantity of holes will increase within the portion of the p-type region aloof from the junction, and it's reduced within the portion of the p-type region nearer to the terminal per se holes area unit shifted from terminal to junction.

• Due to the upper concentration of holes adjacent to the negative impurity ions layer, the electrons of negative ions commence and recombine with those holes and make new holes within the layer. Consequently, the dimension of this negative ions layer is reduced, and at last, this layer vanishes.

• Similarly, because of the negative terminal of the supply, the free electrons within the n-type region can repeal towards the junction wherever they're going to notice the layer of positive impurity ions and begin recombine with these ions and generate free electrons within the layer. Consequently, the dimension of positive impurity ions is reduced, and at last, it vanishes.

• In these ways in which, each layers of ions disappear, and there'll be no a lot of depletion layer. when the depletion layer disappeared, free electrons from the n-type region will simply drift to the p-type region and holes from the p-type region to the n-type region within the crystal.

• Hence, ideally, there'll be no obstruction of flowing current, and therefore the PN junction behaves because the contact.

Refer to the following attachment: