The difference between avalanche breakdown and zener breakdown are given below:
| Avalanche breakdown | Zener breakdown |
|---|---|
| It occurs in junctions which are lightly and have wide depletion widths.. | It occurs in junctions which are heavily doped and have narrow depletion widths. |
| It occurs at higher reverse voltages when thermally generated electrons get enough kinetic energy to produce more electrons by collision. | It occurs due to rupture of covalent bonds by strong electric fields set up in depletion region by the reveres voltage. |
| At reverse voltages above 6 V, breakdown is due to avalanche effect. | At reveres voltage below 6 V, breakdown is due to zener effect. |
| Charge carriers obtain energy from the applied potential. | Zener current is independent of applied voltage. |
| Electron hole pairs are generated. | Large number of holes and electrons are produced |
| Electric field produced is weak in nature. | A strong electric field is produced. |