Hydrothermal synthesis and characteristic photoluminescence of Er-doped SnO2 nanoparticles

We report the characteristic photoluminescence (PL) spectra of erbium ion (Er3+)-doped tin dioxide (SnO2)nanoparticles. The materials were prepared via hydrothermal method at 180 °C with in 20 h by using various Er3+ ion concentrations ranging from 0.0 to 1.0 at%. After the synthesis, the materials were characterized through X-ray diffraction and high-resolution transmission electron microscopy. Crystallite SnO2 and its average particle diameter of approximately 5 nm did not change with Er3+ ion dopant concentration. Photoluminescence spectra showed the characteristic light emission from the Er3+ ions. The PL excitation spectra referred to an efficient energy transfer to Er3+ ions in the presence of SnO2nanoparticles. The most intense Er-related emission of SnO2:Er3+ nanoparticles in near infrared region was found in samples containing an Er3+ ion concentration of 0.25 at%. Although the absorption bandgaps of the materials were identified at approximately 3.8 eV, we found that efficient excitation comes with low excitation energy band edge. Excitation is possibly involved in shallow defects in SnO2 nanoparticles.