IMPACT IONIZATION AND LIGHT-EMISSION IN INALAS INGAAS HETEROSTRUCTUREFIELD-EFFECT TRANSISTORS/

We present measurements on impact ionization effects, real space trans fer of holes and electrons, and light emission occurring in n-channel InAlAs/InGaAs heterostructure Field-Effect Transistors based on InP op erated at high electric fields and at different temperatures. The chan nel electrons heated by the lateral electric field give rise to impact ionization and light emission. By comparing the electrical characteri stics and the integrated light intensity in different energy ranges an d at different temperatures, we were able to identify two main differe nt light emission mechanisms: conduction to conduction-band transition s for low energy photons and conduction to valence-band transitions fo r high energy photons. The correlation between the gate current and th e light intensity allowed us to separately evaluate the electron and h ole components of the gate current.