Rectifying n-n and p-p and non-rectifying p-n abrupt semiconductor heterojunction diodes

Compound Semiconductor Heterojunction Devices are gaining importance in both fast-switching/microwave (HEMT, HBT) and also electro-optic (LASER, HAPD) devices. We analyse on the basis of a simple model what abrupt heterojunctions are expected to be rectifying and non rectifying. We conclude that only anisotype heterojunctions with the p side with the smaller workfunction can be non rectifying and give numerical examples using several semiconductors.