Photoluminescence in laser-annealed neutron transmuted silicon: isoelectronic traps

A Q-switched ruby laser is used to laser-anneal neutron transmuted silicon. The starting material was ultra high purity silicon. Approximately 2 × 1014 P/cm3 were created by the neutron transmutation doping. Photoluminescence measurements at T = 1.7, 4.2, and 20 K revealed long-lived sharp emission lines which were identified with an isoelectronic trap remaining in the laser-annealed material. P-related luminescence was not observed before or after laser annealing.