A Generalized Automated Framework for Thermal Characterization: From Bulk Materials to Complex Heterostructures

Precise determination of thermal conductivity in multilayer structures remains a critical challenge for advancing thermoelectric technologies. Conventional techniques often struggle with surface roughness or require complex preparation, hindering the characterization of electrodeposited materials. To address this gap, a fully automated, MATLAB-based computational framework operationalizing the generalized photoacoustic theory for a robust inverse analysis is presented. The methodology is rigorously benchmarked against Bi₂Te₃/3D anodic aluminum oxide (3D-AAO) reference nanocomposites, reproducing established literature values with high fidelity. Subsequently, the capability of this framework is demonstrated through the characterization of electrodeposited copper selenide (Cu_xSe) films. Results reveal a systematic dependence of thermal conductivity on copper stoichiometry, offering insights into anharmonicity-driven phonon scattering mechanisms. Comprehensive sensitivity analyses confirm that the photoacoustic signal is predominantly dominated by the film's thermal conductivity. Thus, this work delivers an accessible, validated tool for in situ characterization of structurally non-ideal films, accelerating next-generation energy material development.