The effect of different surface orientations on the defect structure of single crystals and the evolution of the luminescence properties under plastic deformation were investigated by cathodoluminescence microscopy. The main features of the spectra were an infra-red band at 1.53eV, and a complex band in the visible range, whose peak position depended upon the electron beam energy and was attributed to O vacancy related defects. Comparison of the intensity of these bands in spectra recorded at low electron beam voltages indicated that the Ti3+ defects had a higher concentration at the (110) surface, whereas the (100) surface had a more complex defect structure that was related to O vacancies. Competition was observed between the visible and infra-red emission centres during plastic deformation; in agreement with the differing diffusion mechanisms of the defects involved in the emissions.

Cathodoluminescence Study of Defects in Deformed (110) and (100) Surfaces of TiO2 Single Crystals. Fernández, I., Cremades, A., Piqueras, J.: Semiconductor Science and Technology, 2005, 20[2], 239-43