Abstract

The high speed response of avalanche photodiodes (APDs) is degraded by hole trapping at the heterointerface between the separated absorption and multiplication region. The photo-excited holes are trapped in a triangular quantum well formed at the heterojunction and escape from the quantum subbands only by thermionic emission. Practically, the insertion of a thin quaternary layer at the heterojunction (QI structure) has been successful in eliminating hole trapping. However, to design the proper transition region at the heterojunction, a quantum mechanical simulation model describing hole transport is required.

© 1991 Optical Society of America