SPM Physics: Semiconductor Diode

In SPM, u must be able to describe semiconductor diode. How to describe it??

• When p-type & n-type semiconductor is joined together, a semiconductor diode is produced.
• At p-n jucntion, a depletion layer is formed when the electron from the n-type fill in the hole in the p-type.
• Connecting p-type to the +ve terminal and n-type to the -ve terminal causing the electron in the n-type to be pulled and filled in the holes across the junction. This movementof electron allow current to flow, thus the diode is forward biased.  
• When the connection is reversed i.e p-type to -ve terminal & n-type to the +ve terminal, the diode is reverse biased. Electron is pulled away from crossing the jucntion, thus no current is flowing.
• This shows that diode allow current to flow in one direction only.

Then u must appreciate the function of diode as rectifier. What is rectifier???

Diode as rectifier can convert AC current into DC current.

The process of conveting AC to DC current is known as rectification. There are two type of rectification that u need to understand in SPM. For each case u must hafal the waveform and its circuit connection. Lets analyse both of them;

1. Half wave rectification (refer to your book, then watch this!)

2. Full wave rectification (refer to your book, then watch this!)



After knowing the different waveform produce for those rectifiers..u also need to draw the waveform appear due to capacitor smoothing effect. Make sure u refer them back in your reference book.