From this video after 1:28. I'm wondering, why are there only some of electrons go past through the P-type and stop flowing.
If P-type still has more hole. I think electrons should never stop flowing until it's equal for N-type and P-type.

 

Why do the charge carriers (electrons) near the junction move across the junction? Are they just happy or is there some 'force' that causes them to move when the junction is created. As the charge carriers move in response to this force what happens to the free charge carriers in the depletion zone. Remember, a material with no free charge carriers is called an insulator.