SnO 2 nanoparticles in the 50-150 nm size range were grown by a low temperature hydrothermal process, using SnCl 4 ·5H 2 O as precursor and CH 3 ͑CH 2 ͒ 15 N͑Br͒͑CH 3 ͒ 3 as stabilizing agent. The as-grown samples were mostly amorphous and their crystallinity improved either by prolonged hydrothermal process or by air annealing at high temperatures. The absence of near-band-edge emission and appearance of a broad visible emission related mainly to oxygen vacancies and crystalline defects were

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... e main characteristics of their room temperature cathodoluminescence ͑CL͒ spectra. A luminescent band in the 1.79-1.83 eV spectral region was also detected. The intensity of the defect bands reduces both on prolonged hydrothermal treatment and air annealing at high temperatures, indicating a net decrease of defect content on thermal treatments. Panchromatic CL images revealed that most of the defect emissions come from smaller SnO 2 nanoparticles.