【International Papers】Iron Dopant Energy Levels in β-Ga₂O₃

      Researchers from the University of Illinois Chicago have published a dissertation titled " Iron dopant energy levels in β-Ga₂O₃ " in Applied Physics Letters.

Abstract

      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.

FIG. 1. Spectral dependence of the transmission (right axis) and αl (left axis) for the Fe:Ga₂O₃(010) wafer: experimental transmission (open blue circles), (1 − R)² using refractive index (dashed black line), (1 − R)²S with S = 0.919 (solid black line), and extracted values of αl (black points) and their fit to two linear functions (solid and dashed red lines).

FIG. 2. Spectral dependence of the square root of the QE for Fe:Ga₂O₃(010): fit for ℏω < 3.8 eV using Eq. (3) (dashed blue line) and fit for ℏω < 4.8 eV using Eq. (4) (solid red line).

DOI：doi.org/10.1063/5.0213263