Nanoscale-shape-mediated coupling between temperature and densification in intense pulsed light sintering
Nanoscale-shape-mediated coupling between temperature and densification in intense pulsed light sintering
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DOI：
10.1088/0957-4484/27/49/495602
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发表时间：
2016-12-09
期刊：
影响因子：
3.5
通讯作者：
Malhotra, R.
中科院分区：
文献类型：
--
作者：
Bansal, S.;Malhotra, R.
在强脉冲光烧结（IPL）中，来自氙灯的脉冲大面积可见光被纳米颗粒膜或图案吸收并转化为热量，导致纳米颗粒的快速烧结。本工作实验表征了银纳米粒子薄膜的强脉冲光。一个新观察到的转折点，在IPL过程中的薄膜温度的演变相关的观察，在文献中，在这项工作中，薄膜致密化水平超过了临界脉冲能量密度和脉冲数。耦合电磁有限元分析，传热模型和致密化模型的计算模型，以预测在IPL的膜的温度和密度的演变。该模型能够捕获IPL期间实验观察到的温度转折点，而IPL的当前模型无法做到这一点。结果表明，温度转折点的发生是由于纳米颗粒膜中光吸收和致密化之间的耦合，并由颗粒间颈部生长导致的沉积纳米颗粒纳米级形状的变化介导的。此外，发现与脉冲的数量相比，每个脉冲的光通量对IPL中可实现的膜密度具有更大的影响。
In intense pulsed light sintering (IPL), pulsed large-area visible light from a xenon lamp is absorbed by nanoparticle films or patterns and converted to heat, resulting in rapid sintering of the nanoparticles. This work experimentally characterizes IPL of silver nanoparticle films. A newly observed turning point in the evolution of film temperature during IPL is correlated to the observation, in literature and in this work, that film densification levels off beyond a critical pulse fluence and number of pulses. A computational model is developed that couples electromagnetic finite element analysis, heat transfer models and densification models to predict the evolution of film temperature and density during IPL. This model is able to capture the experimentally observed turning point in temperature during IPL, whereas current models of IPL are unable to do so. It is shown that the temperature turning point occurs due to a coupling between optical absorption and densification in the nanoparticle film, mediated by a change in nanoscale shape of the deposited nanoparticles due to interparticle neck growth. Further, it is found that the optical fluence per pulse has a greater effect on the achievable film density in IPL, as compared to the number of pulses.