Synthesis of bright multicolor down and upconversion emitting Y2Te4O11:Er:Yb nanocrystals

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights•Monoclinic Er:Yb:Y2Te4O11 nanocrystals synthesized using solid state method.•Detailed radiative properties explored on 266 and 976 nm excitations.•Bright Stokes and Anti-Stokes emissions reported for these excitations.•Energy transfer was reported from charge transfer (Yb–O) → Er ions.•Efficient nonradiative energy transfer was reported from Yb → Er ions.

Present article report on synthesis, structural and detailed radiative characterizations of Er and Er:Yb codoped novel monoclinic Y2Te4O11 nanocrystals. Structural properties were explored using XRD, SEM while electronic-vibrational energy levels were monitored by UV-FTIR absorption techniques. Detailed Stokes and anti-Stokes were investigated on 266 and 976 nm excitations in steady state and in time domain. Back and forth energy transfer from Er → Yb and Yb → Er ion was observed on 266 and 976 nm laser excitations, respectively. UV/Vis upconversion emissions are reported on excitation with 976 nm laser excitation via successive three photon absorption, and intensity of which further increase due to efficient nonradiative energy transfer from Yb3+ ions. In brief, the efficient bright emission observed in Y2Te4O11 nanocrystals for all the excitations spanning in wide spectral range. The photophysics involved in these emissions were also explained.