Question

ii. If you wanted to double the electron current, what should you do? Q5. (a) Two different breakdown mechanisms are shown in the diagram below. Identify the mechanisms and explain any one of them. ?? (b) Use the graph below to calculate the breakdown voltage for a silicon one-sided p-n abrupt junction with a donor concentration No-1x10"/cm 12 ????? Q6. (a) Make a table comparing 5 major features of the inversion mode s

Answer 1

a) First one (a) Zenor break down - small reverse bias This occurs at function which being heavily doped have narrow depletion layer This breakdown voltage sets a very strong electric field across this narrow layer Here electric field very strong to replace the covalent bonds there by generating electron - hole pairs so even a small increase in reverse voltage is capable of producing large number of current carrers Zenor diode exhibits negative temp coefficient ie break down voltage decreases as temperature increases b) second one (b) Avalanche break down mechanism Depletion width larger than mean free path of collision This occurs at function which bearing lightly doped have width depletion layers \r\n Here electric field is not strong enough to produce zenor break down Her minority carres collides with semi conductor atoms in the depletion region which break the covalent bonds and electrons hole pair are generated newly generated charge are accelerated by the electric field which