Upconversion thermometry: a new tool to measure the thermal resistance of nanoparticles

We demonstrated that KLu(WO₄)₂:Ho³⁺,Tm³⁺ nanoparticles are able to combine controllable heat release and upconversion thermometry permitting to estimate the thermal resistance of the nanoparticles in air, a key parameter to model the heat transfer at the nanoscale.