Electron paramagnetic resonance measurements performed at 4.2K, and photoluminescence spectra obtained at 20K, were used to study point defects in crystals which had been grown via the travelling heater method. Isotropic and anisotropic paramagnetic centres were found in crystals which were as-grown or annealed in various gaseous ambients. Three photoluminescence bands were observed, and the effects of H2, O2 and Se2 annealing were studied. The presence of donor singlet, VSe+, was detected in as-grown and H-annealed crystals. A study of electron paramagnetic resonance data, photoluminescence spectra and defect physics models suggested the existence of point defect ensembles; with 2VCu-+GaCu2+, VCu and other complexes, depending upon the treatment used.

Electron Paramagnetic Resonance and Photoluminescence Study of Defects in CuGaSe2 Single Crystals Grown by the Travelling Heater Method. T.Nishi, G.A.Medvedkin, Y.Katsumata, K.Sato, H.Miyake: Japanese Journal of Applied Physics - 1, 2001, 40[1], 59-63