Question about pn diodes and their lifetime

[DIY9000]

I was wondering, does the lifetime of a diode depend on how long it takes for all the free P electrons to transfer over to the p holes? In other words, do the electrons that fall into the p holes ever return to the n side?

 

[mfb]

I was wondering, does the lifetime of a diode depend on how long it takes for all the free P electrons to transfer over to the p holes?

No.

In other words, do the electrons that fall into the p holes ever return to the n side?

It depends on the current applied, they can also leave the diode. Other electrons come in from the other side, so there is never a lack/surplus of electrons. There is no "lifetime" in that sense. You can fry a diode if it gets too hot, you can kill it with radiation damage, mechanical damage and a few other things, but apart from that diodes live forever. Electron flow is always balanced.

 

[M Quack]

Electrons come and go, it's the ions that stay. The diode is destroyed when the crystal structure with the p and n doping gets destroyed, e.g. by overheating. Just as mfb said above.