It was noted that, upon illumination, some structural defects in irradiated material could be excited into metastable triplet states which might be involved in the excess-carrier recombination process. Here, a theoretical analysis was made of spin-dependent recombination via an excited triplet state. The properties of its electron paramagnetic resonance spectra were deduced from direct-current and microwave photoconductivity changes which occurred under magnetic resonance conditions. The dependence of the spectral line intensity upon experimental parameters such as the microwave power and specimen size was investigated. By using the spin-dependent recombination technique, the angular dependence of the line positions and intensities for structural defects in their excited triplet states was studied and the spin-Hamiltonian parameters of various spectra were determined.

L.S.Vlasenko, J.V.Martynov, T.Gregorkiewicz, C.A.J.Ammerlaan: Physical Review B, 1995, 52[2], 1144-51