On the self-damping nature of densification in photonic sintering of nanoparticles.
On the self-damping nature of densification in photonic sintering of nanoparticles.
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DOI：
10.1038/srep14845
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发表时间：
2015-10-07
影响因子：
4.6
通讯作者：
Malhotra R
中科院分区：
文献类型：
--
作者：
MacNeill W;Choi CH;Chang CH;Malhotra R
在大面积基底上烧结纳米粒子墨水是可扩展制造图案化和连续薄膜的关键推动因素，具有多种新兴应用。光子烧结的高速和环境条件操作引起了人们对此的极大兴趣。在这项工作中，我们通过实验表征了银纳米颗粒墨水光子烧结中的温度演变和致密化，作为纳米颗粒尺寸的函数。结果表明，与较大的纳米颗粒相比，较小的纳米颗粒导致更快的致密化，并且烧结过程中的温度较低。此外，即使没有纳米颗粒熔化也可以实现高致密化。光子加热的电磁有限元分析与分析烧结模型相结合，以检查光子烧结中颗粒间颈部生长的作用。结果表明，光子烧结本质上是一种自阻尼过程，即，即使在达到全密度之前，致密化的进展也会降低后续光子加热的幅度。通过考虑这种现象，与传统的光子烧结模型相比，开发的耦合模型更好地捕捉了实验观察到的烧结温度和致密化。此外，该模型用于揭示实验观察到的致密化随较小纳米颗粒与较大纳米颗粒的重量比增加而增加的原因。
Sintering of nanoparticle inks over large area-substrates is a key enabler for scalable fabrication of patterned and continuous films, with multiple emerging applications. The high speed and ambient condition operation of photonic sintering has elicited significant interest for this purpose. In this work, we experimentally characterize the temperature evolution and densification in photonic sintering of silver nanoparticle inks, as a function of nanoparticle size. It is shown that smaller nanoparticles result in faster densification, with lower temperatures during sintering, as compared to larger nanoparticles. Further, high densification can be achieved even without nanoparticle melting. Electromagnetic Finite Element Analysis of photonic heating is coupled to an analytical sintering model, to examine the role of interparticle neck growth in photonic sintering. It is shown that photonic sintering is an inherently self-damping process, i.e., the progress of densification reduces the magnitude of subsequent photonic heating even before full density is reached. By accounting for this phenomenon, the developed coupled model better captures the experimentally observed sintering temperature and densification as compared to conventional photonic sintering models. Further, this model is used to uncover the reason behind the experimentally observed increase in densification with increasing weight ratio of smaller to larger nanoparticles.