A high precision infrared emissivity measurement method for micro/ nano structures

The potential of micro/nano structures in regulating thermal radiation for infrared stealth, radiation cooling, and energy harvesting has attracted significant research interest. However, the radiation from optical components and the surrounding environment poses a challenge to the accurate measurement of thermal radiation of micro/ nano samples in laboratory environments. In this study, a background-separated spectral emissivity measurement method was designed, employing two standard reference samples to isolate the sample background and optical component background from the measurement signal of the Fourier Transform Infrared (FTIR) spectrometer. Accurate measurement of infrared spectral emissivity was achieved by analyzing the temperature variations of the sample and optical component backgrounds. To validate this method, a Pt/Cr/Si emitter was designed and fabricated. The measured spectral emissivity of the micro/nano sample was consistent with the simulation results, demonstrating the effectiveness of the background-separated emissivity measurement method. This study provides an effective approach for measuring the spectral emissivity of micro/nano samples above room temperature and separating the thermal radiation background during the measurement process.