Near Infrared Quantum Cutting Luminescence of Er/Tm Ion Pairs in a Telluride Glass.

The multiphoton near-infrared, quantum cutting luminescence in Er/Tm co-doped telluride glass was studied. We found that the near-infrared 1800-nm luminescence intensity of (A) Er(8%)Tm(0.5%):telluride glass was approximately 4.4 to 19.5 times larger than that of (B) Tm(0.5%):telluride glass, and approximately 5.0 times larger than that of (C) Er(0.5%):telluride glass. Additionally, the infrared excitation spectra of the 1800 nm luminescence, as well as the visible excitation spectra of the 522 nm and 652 nm luminescence, of (A) Er(8%)Tm(0.5%):telluride glass are very similar to those of Er ions in (C) Er(0.5%):telluride glass, with respect to the shapes of their excitation spectral waveforms and peak wavelengths. Moreover, we found that there is a strong spectral overlap and energy transfer between the infrared luminescence of Er donor ions and the infrared absorption of Tm acceptor ions. The efficiency of this energy transfer {I(Er) → I(Er), H(Tm) → F(Tm)} between the Er and Tm ions is approximately 69.8%. Therefore, we can conclude that the observed behaviour is an interesting multiphoton, near-infrared, quantum cutting luminescence phenomenon that occurs in novel Er-Tm ion pairs. These findings are significant for the development of next-generation environmentally friendly germanium solar cells, and near-to-mid infrared (1.8-2.0 μm) lasers pumped by GaN light emitting diodes.