Assessment of electrical and optical properties of heavily Fe-implanted semi-insulating InP

We report total compensation of InP layers n-doped to levels as high as n=2×1018 cm−3 by high temperature (>200°C) MeV Fe implantation and annealing. The electronic density and the active Fe (in the form of the Fe2+/Fe3+ deep acceptor states) profiles are obtained from the comparison between the current–voltage (I–V) characteristics and the outcome of a numerical simulation. These results are confirmed by photo-induced current transient spectroscopy (PICTS) experiments, which show a correlation between the Fe activation and the background doping concentration. A deeper insight into the properties of the Fe2+/Fe3+ centers is gained by Fourier transform infrared (FTIR) photoluminescence measurements, showing intense and sharp emission peaks at 3.5 μm, associated with Fe intracenter transitions. The corresponding lifetimes have been studied by time resolved integrated photoluminescence measurements.