Understanding Reverse Biasing In A Diode

[Hazmatac]

I don't understand how reverse biasing works. Specifically, I don't understand what is drawing the holes in the silicon to the battery, thereby widening the depletion region on the n side. 

[kesaraP]

I know this is a old thread. But I would like to submit a answer because it could be helpful to someone that have same question.

In reverse bias positive terminal of the battery is connected to the positive terminal of the PN junction. The positive terminal of the depletion layer occurred in N type region. That means there are more negative charges. When positive terminal is connected to the N type region, negative charges will attracted to the positive terminal. That means the positive region is widen. This similar phenomenon is occurred on negative terminal also. That cause the widen of negative region. This overall process caused to widen the depletion layer.

Also if you are interested in here you can read about PN junction. It contains more graphical explanation about the reverse biasing of a PN junction.