Optical and electrical characterization of nitrogen ion implanted ZnSSe/p-GaAs (100)

Nitrogen ions were implanted into ZnS_xSe_1-x epilayers grown on p-GaAs (100) substrates by molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD). Dopant activation and annealing out the implant damage were achieved by a postannealing process in a N₂ ambient. Schottky structures employing the implanted p-type ZnS_xSe_1-x were fabricated and device efficacy was examined by photoluminescence (PL) spectroscopy, current-voltage (I-V), current-voltage temperature (I - V - T), and high frequency capacitance-voltage (C - V) measurements. PL spectra showed a clear donor-acceptor pair (DAP) recombination at an energy of 2.735 and 2.72 eV, in both MBE and MOCVD ZnSSe epilayers, respectively, regardless of the postannealing temperatures. The diode conduction in forward bias proceeds by the combination of thermionic and tunneling emission. C - V measurement proved the maximum doping concentration to be around 10¹⁷ cm^-3 after ion implantation.