Cooling of Er(3+) with Tm(3+) for accurate temperature sensing using yttrium silicate compact powders

Er(3+) doped nanocrystalline powders are extensively used for thermometry based on luminescence spectral analysis. The luminescence from Er(3+) is produced by a nonlinear (two-photon) absorption process which may generate strong internal heat by activation of nonradiative relaxation channels. If the heat dissipation is not efficient, as is the case for compact powders, there will be inaccurate readings of the temperature. Our proposed solution is to cool down Er(3+) by transferring part of its accumulated energy to another rare-earth element in the lattice. Here, we show our results for Er(3+)-Tm(3+) co-doped yttrium silicate powders prepared by combustion synthesis.