How a semiconductor diode(pn junction) works

Below is a very straight forward diagrammatic explanation of how the diode works.

A diode is just a p and n type semiconductor material joined together.

As soon as the junction is made, there will be a rush of the charged particles. The majority and minority carriers from n region will rush into the p region and the same from p region will rush into the n region. They are the carriers of the current. Now, the minority carriers too transport themselves and the reverse current and the forward current is equal, its just a basically rush of the particles moving from their own respective region to the other region simply because they dont have anyone to stop them. They are badass people. But with no actual use. The total amount of current will still be zero. Hence, if there is no external bias, there will be no current. Cool makes sense. Also, it might seem illogical for the elctron from n type material to actually go into the p region, although they have to overcome the attractive forces, they have still enough kinetic energy.The current her is called diffusion current.

But the rush is limited to only a certain region. The entire block of our material isn't going to be affected and technically replaced, but a small region near the junction. Hence the depletion region being formed as shown in the figure.

Now a bias is applied, positive bias. The relevant charged particles will be pushed, the depletion layer will be reduced and the current will flow. For the reverse bias, the depletion region will expand giving no chance for the charged particles to move hence no or very little current. The current under bias is drift current.

Youtube links-
https://www.youtube.com/watch?v=JBtEckh3L9Q
https://www.youtube.com/watch?v=OyC02DWq3mI