The photoacoustic measurement technique is a powerful yet underrepresented method to characterize the thermal transport properties of thin films. For the case of isotropic low thermal diffusivity samples, such as glasses or polymers, we demonstrate a general approach to extract the thermal conductivity with a high degree of significance. We discuss in particular the influence of thermal effusivity, thermal diffusivity, and sample layer thickness on the significance and accuracy of this measurement technique. These fundamental thermal properties guide sample and substrate selection to allow for a feasible thermal transport characterization. Furthermore, our data evaluation allows us to directly extract the thermal conductivity from this transient technique, without separate determination of the volumetric heat capacity, when appropriate boundary conditions are fulfilled. Using silica, poly(methyl methacrylate) (PMMA) thin films, and various substrates (quartz, steel, and silicon), we verify the quantitative correctness of our analytical approach.

光声测量技术是表征薄膜热传输特性的一种功能强大但代表性不足的方法。对于各向同性的低热扩散率样品（例如玻璃或聚合物），我们演示了一种提取热导率的通用方法，具有很高的意义。我们特别讨论了热效率，热扩散率和样品层厚度对这种测量技术的重要性和准确性的影响。这些基本的热特性指导样品和基材的选择，以实现可行的热传输特性。此外，我们的数据评估使我们可以直接从这种瞬态技术中提取热导率，而无需单独确定体积热容，当适当的边界条件得到满足时。我们使用二氧化硅，聚甲基丙烯酸甲酯（PMMA）薄膜和各种基材（石英，钢和硅），验证了我们分析方法的定量正确性。