Scott Ethan A, King Sean W, Jarenwattananon Nanette N, Lanford William A, Li Han, Rhodes James, Hopkins Patrick E
Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904, United States.
Logic Technology Development, Intel Corporation, Hillsboro, Oregon 97124, United States.
Nano Lett. 2021 May 12;21(9):3935-3940. doi: 10.1021/acs.nanolett.1c00616. Epub 2021 Apr 22.
Amorphous solids are traditionally assumed to set the lower bound to the vibrational thermal conductivity of a material due to the high degree of structural disorder. Here, were demonstrate the ability to increase the thermal conductivity of amorphous solids through ion irradiation, in turn, altering the bonding network configuration. We report on the thermal conductivity of hydrogenated amorphous carbon implanted with C ions spanning fluences of 3 × 10-8.6 × 10 cm and energies of 10-20 keV. Time-domain thermoreflectance measurements of the films' thermal conductivities reveal significant enhancement, up to a factor of 3, depending upon the preirradiation composition. Films with higher initial hydrogen content provide the greatest increase, which is complemented by an increased stiffening and densification from the irradiation process. This enhancement in vibrational transport is unique when contrasted to crystalline materials, for which ion implantation is known to produce structural degradation and significantly reduced thermal conductivities.
由于高度的结构无序性，传统上认为非晶态固体为材料的振动热导率设定了下限。在此，我们展示了通过离子辐照提高非晶态固体热导率的能力，进而改变键合网络构型。我们报告了注入碳离子的氢化非晶碳的热导率，碳离子的通量范围为3×10⁻⁸至6×10²¹/cm²，能量为10至20 keV。对薄膜热导率的时域热反射测量显示，根据预辐照组成，热导率显著提高，最高可达3倍。初始氢含量较高的薄膜热导率增加最大，这与辐照过程中增强的硬化和致密化相辅相成。与晶体材料相比，这种振动传输的增强是独特的，已知离子注入会使晶体材料产生结构退化并显著降低热导率。
