Boltzmann-Distribution-Driven Cathodoluminescence Thermometry in In Situ Transmission Electron Microscopy

Abstract

Nanothermometry in in situ transmission electron microscopy (TEM) is useful for comprehending the functioning mechanisms of the heterogeneous matter through real-time observations. Herein, we introduce a Boltzmann-distribution-driven cathodoluminescence (CL) nanothermometry for in situ local temperature probing in TEM. The population distribution across the close-lying Stark sublevels of dysprosium ions in an yttrium vanadate matrix follows the Boltzmann distribution, enabling the use of the CL-intensity ratio as a thermometry over a wide temperature range of 103-435 K with a relative sensitivity exceeding 3% K-1 and precision of +/- 2%. Superior to other CL-based thermometries, the present approach is independent of electron-beam parameters and dopant concentration, extending the robustness and applicability of CL-based nanothermometry in electron microscopy. We further demonstrate the real-time mapping of the temperature distribution across a TEM grid under laser irradiation.