Extreme near-field heat transfer between gold surfaces
Extreme near-field heat transfer between gold surfaces
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DOI：
10.1103/physrevb.104.125404
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发表时间：
2021-02
影响因子：
3.7
通讯作者：
T. Tokunaga;Amun Jarzembski;T. Shiga;Keunhan Park;M. Francoeur
中科院分区：
文献类型：
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作者：
T. Tokunaga;Amun Jarzembski;T. Shiga;Keunhan Park;M. Francoeur
金属表面间的极端近场热传递是一个有争议的话题，因为最先进的理论和实验在驱动热传递的能量载体上存在分歧。为了阐明金属表面之间的极端近场热传递的物理学，这封信提出了一个综合的模型，结合辐射，声学声子和电子输运跨越亚10纳米真空间隙。金表面的结果表明，在偏压的情况下，声学声子输运是占主导地位的真空间隙小于2 nm。偏置电压的施加显著地影响主导能量载流子，因为它增加了由长程库仑力介导的声子贡献和由于较低势垒引起的电子贡献。对于0.6 V的偏置电压，声学声子输运在5 nm的真空间隙处占主导地位，而电子隧穿在亚1 nm的真空间隙处占主导地位。理论与文献中的实验数据的比较表明，金属表面之间的良好控制的测量需要量化的声学声子和电子作为偏置电压的函数的贡献。
Extreme near-field heat transfer between metallic surfaces is a subject of debate as the state-of-the-art theory and experiments are in disagreement on the energy carriers driving heat transport. In an effort to elucidate the physics of extreme near-field heat transfer between metallic surfaces, this Letter presents a comprehensive model combining radiation, acoustic phonon and electron transport across sub-10-nm vacuum gaps. The results obtained for gold surfaces show that in the absence of bias voltage, acoustic phonon transport is dominant for vacuum gaps smaller than ~2 nm. The application of a bias voltage significantly affects the dominant energy carriers as it increases the phonon contribution mediated by the long-range Coulomb force and the electron contribution due to a lower potential barrier. For a bias voltage of 0.6 V, acoustic phonon transport becomes dominant at a vacuum gap of 5 nm, whereas electron tunneling dominates at sub-1-nm vacuum gaps. The comparison of the theory against experimental data from the literature suggests that well-controlled measurements between metallic surfaces are needed to quantify the contributions of acoustic phonon and electron as a function of the bias voltage.