ODMR studies of antisite-related luminescence in GaP

By the use of ODMR, we have detected and identified two different antisite defects which contribute to newly-reported infrared luminescence observed in GaP. The antisite proper, P_Ga, gives rise to a spin-$\text{1}\text{2}$ resonance; the associated luminescence originates in the DA pair recombination of an electron trapped at the deep double donor P⁺_Ga with a distant shallow acceptor. An impurity-associated centre of the form P_Ga · Y_P is observed in a spin-triplet state via a distinct luminescence band which originates in electron-hole recombination localised at the defect.