Photoluminescence properties of SnO2 nanowhiskers grown by thermal evaporation

SnO2 nanowhiskers were synthesized by thermal oxidation with and without a gold film as a catalyst. The SEM images reveal wire-like and rod-shaped nanowhiskers about several hundred micrometers in length and 100 nm in diameter. The three observed Raman peaks at 474, 632, and 774 cm−1 indicate the typical rutile phase which is in agreement with the X-ray diffraction results. The photoluminescence properties were measured at room temperature. The peaks at 342 nm corresponding to the excitation transitions from the conduction band to the valence band of the SnO2 nanowhiskers were not observed. However, a strong emission band at ∼600 nm was detected indicating the existence of oxygen vacancies in both samples. A new emission band at ∼398 nm was also observed in the sample with the gold film and it could be attributed to the near band-edge emission.