Electrical and optical properties of p-GaN films implanted with transition metal impurities

Electrical and optical properties and the spectra of deep hole traps in p-GaN films implanted with high doses (3 × 1016 cm−3) of Co,Mn, Fe and Cr and annealed at 700 °C are reported. The dominant deep traps generated by this implantation are of the same type as observed in similar films heavily implanted with protons. The magnitude of the changes in the conductance and transmission of the GaN correlates with the atomic mass of the transition metal ions and the density of primary radiation defects. For fabrication of spintronic devices such as spin-LEDs using implantation of the TM species into the top p-GaN contact layer, the best results should be expected using Cr implantation since this produces both room temperature ferromagnetism and the smallest reduction in conductivity of the p-GaN.