ABSTRACT

Micro-Raman thermometry is an effective method for measuring thermal conductivity of thin films. It features noncontact and nondestructive probing and convenience of sample preparation. However, there is a concern of its accuracy when using the Raman peak shift as the temperature transducer since it responds to both temperature and strain upon optical heating. In this work, a series of detailed experiments are carried out to evaluate contributions to Raman signals from temperature only vs. from thermomechanical strain. It is shown that using proper calibration, contributions to Raman signals from temperature only and from thermomechanical strain can be decoupled and thermal conductivity can be evaluated correctly. These procedures are then applied to bismuth telluride thin films to illustrate measurement of thin film thermal conductivity.

摘要

显微拉曼测温法是一种测量薄膜热导率的有效方法。它具有非接触和无损探测和样品制备方便的特点。然而，当使用拉曼峰位移作为温度传感器时，它的准确性存在问题，因为它对光学加热时的温度和应变做出响应。在这项工作中，进行了一系列详细的实验来评估仅来自温度与来自热机械应变的拉曼信号的贡献。结果表明，使用适当的校准，可以消除仅来自温度和热机械应变对拉曼信号的贡献，并且可以正确评估热导率。然后将这些程序应用于碲化铋薄膜，以说明薄膜热导率的测量。