论文标题
将缺陷/杂质和皱纹在晶片尺度HBN膜的导热率中的作用解耦
Decoupling the Roles of Defects/Impurities and Wrinkles in Thermal Conductivity of Wafer-scale hBN Films
论文作者
论文摘要
我们证明了厚度厚度的大面积六角硼卫星膜的导热率的非单调演变。这些电影中存在皱纹和缺陷/杂质。拉曼光谱是一种选择性非接触技术，用于探测拉曼活跃E2GHIGH呼叫声模式的温度和激光功率依赖性，这又用于估计不同激光功率下膜温度的升高。由于不能直接通过分析使用传统的热扩散定律来评估这些薄膜的导热率，因此使用有限元建模。在模型中，平均耐热性用于结合整体缺陷结构，并且在细胞边界处具有接触电阻的Voronoi细胞被构建以模仿皱纹的域。对于2、10和30 nm厚的膜，有效的热导率估计分别为87、55和117 W/M.K。我们还通过缺陷和皱纹对热流进行了热阻力的定量估计。我们的研究表明，与皱纹相比，缺陷/杂质使膜中对传热的阻力要高得多。
We demonstrate a non-monotonic evolution of thermal conductivity of large-area hexagonal boron nitride films with thickness. Wrinkles and defects/impurities are present in these films. Raman spectroscopy, an optothermal non-contact technique, is employed to probe the temperature and laser power dependence property of the Raman active E2ghigh phonon mode, which in turn is used to estimate the rise in the temperature of the films under different laser powers. As the conventional Fourier law of heat diffusion cannot be directly employed analytically to evaluate the thermal conductivity of these films with defects and wrinkles, finite element modeling is used instead. In the model, average heat resistance is used to incorporate an overall defect structure, and Voronoi cells with contact resistance at the cell boundaries are constructed to mimic the wrinkled domains. The effective thermal conductivity is estimated to be 87, 55, and 117 W/m.K for the 2, 10, and 30 nm-thick films, respectively. We also present a quantitative estimation of the thermal resistance by defects and wrinkles individually to the heat flow. Our study reveals that the defects/impurities render a much higher resistance to heat transfer in the films than wrinkles.
