Abstract
We have investigated band gap states in AlGaN/GaN hetero-structure grown on sapphire substrate, employing capacitance–voltage and capacitance deep-level optical spectroscopy techniques. Two specific deep levels were revealed to be located at ∼1.70 and ∼2.08 eV below the conduction band, being clearly different from the deep-level defects observed in GaN. Both deep levels showed a significant increase in their corresponding steady-state photo-capacitance in partial pinch-off mode. It is thought that these levels probably stem from a two-dimensional electron gas (2DEG) region at the AlGaN/GaN hetero-interface. In particular, the 1.70 eV level is likely to act as an efficient generation-recombination center for 2DEG carriers.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
