POINT-DEFECTS AND SHORT-WAVELENGTH LUMINESCENCE OF LIB3O5 SINGLE-CRYSTALS

The results of the study both on short-wavelength luminescence and poi nt defects in the large LiB3O5 crystals grown by the advanced techniqu e are reported. It was revealed that corpuscular-or photon radiation w ith energy exceeding E(g) efficiently excites the complex broad lumine scence band at 290 nn. Decay kinetics involves a principal fast compon ent with lifetime of 4 ns and several components of millisecond range. On irradiation at 77 K, LiB3O5 crystals yield the new ESR-signals, re sulted from the B(2+)election and O- hole trapped centers which are st able at temperatures below RT. The obtained data suggest that these ce nters are responsible for the radiation-induced optical absorption ban d at 306 nm. We also investigated accumulation and thermal annealing o f the point defects. The most acceptable models of defects, recombinat ion processes with defects participation and the origin of the LiB3O5 short-wavelength luminescence are discussed.