Shape-Tuned Junction Resistivity and Self-Damping Dynamics in Intense Pulsed Light Sintering of Silver Nanostructure Films
Shape-Tuned Junction Resistivity and Self-Damping Dynamics in Intense Pulsed Light Sintering of Silver Nanostructure Films
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DOI：
10.1021/acsami.8b17644
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发表时间：
2019-01-23
影响因子：
9.5
通讯作者：
Malhotra, Rajiv
中科院分区：
文献类型：
--
作者：
Hwang, Hyun-Jun;Malhotra, Rajiv
同时，降低加工温度、电阻和材料成本以及可扩展的制造能力对柔性和平面电子的导电元件至关重要。强脉冲光烧结（IPL）混合异型导电纳米结构可以实现这一目标。然而，对于纳米结构形状的不同如何影响颗粒间颈生长动力学以及颈生长与光吸收之间的自阻尼耦合，这种潜力受到知识空白的阻碍。我们研究了混合银纳米线（NWs，直径40 nm，长度100-200 μ m）和纳米球（NSs，直径40 nm）的IPL现象，并通过实验和分子动力学模拟与光学建模相结合。最佳50:50混合比例降低电阻率(5.59 μ ω。相对于具有相似电阻率的纯NW薄膜，在IPL的2.5 s内，相对于纯NW薄膜，降低了材料成本。连续光脉冲中峰值温度的下降随着NW含量的增加而减小。烧结诱发位错的产生导致NW-NS和NW-NW界面颈长增大，NW-NS界面颈长各向异性增大。这表明，当NWs被引入到NS膜中时，伴随着较少的界面接触点数量，烧结引起的结电阻率的固有降低在降低膜电阻率方面起着主要作用。驱动IPL温度变化的自阻尼耦合和光吸收可以通过纳米结构的形状来调节。在NS系综中引入NWs减少了光吸收对颈部生长的依赖。我们讨论了这些见解如何阐明了一组物理现象，这些现象可以指导选择不同形状的纳米结构，同时降低IPL和其他烧结过程中的电阻率和温度。
Concurrently reducing processing temperature, electrical resistance, and material cost with scalable fabrication capabilities is critical for conductive elements of flexible and planar electronics. Intense pulsed light sintering (IPL) of mixed dissimilar-shape conductive nanostructures may achieve this goal. However, this potential is hindered by knowledge gaps on how dissimilarity in nanostructure shape affects interparticle neck growth kinetics in general and the self-damping coupling between neck growth and optical absorption in IPL. We study these phenomena for IPL of mixed Ag nanowires (NWs, 40 nm diameter, 100-200 mu m length) and nanospheres (NSs, 40 nm diameter), both experimentally and by linking molecular dynamics simulations with optical modeling. An optimal 50:50 mixing ratio lowers resistivity (5.59 mu Omega.cm) and peak temperatures (250-150 degrees C) relative to pure NS films and reduces material costs relative to pure NW films with similar resistivity, in 2.5 s of IPL. The drop in peak temperatures in consecutive optical pulses reduces with greater NW content. Sintering-induced dislocation generation drives higher neck growth at NW-NS and NW-NW interfaces and anisotropic neck growth at NW-NS interfaces. This indicates that when NWs are introduced into NS films, along with lesser number of interfacial contact points, an inherent reduction in sintering-induced junction resistivity plays a major role in reducing film resistivity. The self-damping coupling and optical absorption, which drive temperature evolution in IPL, are tunable by nanostructure shape. The introduction of NWs into a NS ensemble reduces the dependence of optical absorption on neck growth. We discuss how these insights elucidate a set of physical phenomena that can guide the choice of dissimilar shaped nanostructures to concurrently reduce resistivity and temperatures in IPL and other sintering processes.