Iron dopant energy levels in β-Ga2O3.

The energetic positions of the two Fe dopant levels in the bandgap of β-Ga₂O₃ are determined to be at 3.05(±0.05) and 3.85(±0.05) eV below the conduction band minimum from transmission measurements employing a sub-picosecond tunable ultraviolet laser radiation source. A further measurement of the quantum efficiency of photoelectron emission from the Fe:Ga₂O₃(010) photocathode is consistent with the obtained absorption data and a dominant optical phonon assisted Franck–Condon emission mechanism, while also providing an estimate of 100 ps for the conduction band electron lifetime. [ABSTRACT FROM AUTHOR]