Measurement of In-Plane Thermal Conductivity of Ultrathin Films Using Micro-Raman Spectroscopy
Abstract
We report a micro-Raman-based optical method to measure in-plane thermal conductivity of ultrathin films. With the use of 20-nm-thick SiO2 substrates that assure in-plane heat transfer, sub-100-nm Bi films and Al2O3 films as thin as 5 nm were successfully measured. The results of Bi films reveal that phonon boundary scattering, both at the surface/interface and at the grain boundaries, reduces in-plane lattice thermal conductivity. The measurements of amorphous Al2O3 films were accomplished using thin Bi film as a Raman temperature sensor, and the results agree with the minimum thermal conductivity models for dielectrics. Our work demonstrates that the micro-Raman method is promising for characterization of in-plane thermal conductivity and phonon behaviors of thin-film structures if the Raman temperature sensor material and substrate material are carefully selected.
Keywords
thin films, phonon boundary scattering, in-plane thermal conductivity, micro-Raman, THERMOELECTRIC-MATERIALS, HEAT-CONDUCTION, SINGLE-CRYSTALS, THIN-FILMS, TRANSPORT, SUPERLATTICES, SIZE, GRAPHENE, DEVICES
Citation
10.1080/15567265.2014.892553
Date of this Version
4-3-2014
Recommended Citation
Luo, Zhe; Liu, Han; Spann, Bryan T.; Feng, Yanhui; Ye, Peide D.; Chen, Yong P.; and Xu, Xianfan, "Measurement of In-Plane Thermal Conductivity of Ultrathin Films Using Micro-Raman Spectroscopy" (2014). Birck and NCN Publications. Paper 1581.
https://docs.lib.purdue.edu/nanopub/1581