Impact ionization and light emission in InAlAs/InGaAs heterostructure field-effect transistors

We present measurements on impact ionization effects, real space transfer of holes and electrons, and light emission occurring in n-channel InAlAs/InGaGs heterostructure Field-Effect Transistors based on InP operated at high electric fields and at different temperatures. The channel electrons heated by the lateral electric field give rise to impact ionization and light emission. By comparing the electrical characteristics and the integrated light intensity in different energy ranges and at different temperatures, we were able to identify two main different light emission mechanisms: conduction to conduction-band transitions for low energy photons and conduction to valence-band transitions for high energy photons. The correlation between the gate current and the light intensity allowed us to separately evaluate the electron and hole components of the gate current