Photoluminescence of Undoped, Semi-Insulating, and Mg-Implanted Indium Phosphide

摘要

A photoluminescent investigation was made of undoped, semi-insulating, unannealed and annealed Mg-ion implanted, indium phosphide which originated from Czochralski, vapor, and liquid grown crystals. Ion implantation was performed at fluences of 5 x 10 to the 12th power ions/sq cm to 1 x 10 to the 15 power ions/sq cm with an energy of 120 keV at room temperature, followed by annealing at 700 degrees C and 750 degrees C for fifteen minutes using a Si3N4 encapsulant. Luminescence of undoped InP was studied with respect to temperature, emission intensity, and excitation intensity; results included the possible identification of the following radiative recombinations: free exciton, bound exciton, donor-to-valence, and donor-to-acceptor. Broad, low intensity peaks were identified at 1.0541 eV, 0.9374 eV, and 1.15 eV. Spectral results of the less intense semi-insulating InP:Fe were identical to undoped InP aside from a 1.38 eV high energy shoulder and low intensity peak at 1.31 eV. Photoluminescence of unannealed, implanted samples resulted in a 0.9643 eV peak with a long, low energy shoulder. Emission intensity and peak energy of annealed, implanted samples were studied as a function of dosage and anneal temperature. The post-implantation annealing at 750 degree C was sufficient to obtain efficient luminescence. Analysis of the 750 degree C annealed samples indicates that the peak due to recombinations involving implanted Mg acceptors is located between 1.384 eV at 50 degrees K. Superior spectral results from VPE InP places the Mg peak position at 1.3801 eV.