You should be able to recognise the graph of current against voltage for a diode. The diode has a very high resistance in one direction. This means that current can only flow in the other direction.

One is laid bare by [WizardTim], as he cross-sections a 20KV high-voltage diode. A conventional low-voltage silicon diode has a forward voltage drop of about 0.7V and a relatively low maximum ...

This second course provides a more detailed description of high-voltage Schottky and p-n diodes, starting with the semiconductor physics background needed to analyze both types of diodes. The main ...