Modeling nanoscale temperature gradients and conductivity evolution in pulsed light sintering of silver nanowire networks
Modeling nanoscale temperature gradients and conductivity evolution in pulsed light sintering of silver nanowire networks
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DOI：
10.1088/1361-6528/aae368
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发表时间：
2018-12-14
期刊：
影响因子：
3.5
通讯作者：
Malhotra, Rajiv
中科院分区：
文献类型：
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作者：
Dexter, Michael;Pfau, Andrew;Malhotra, Rajiv
在透明聚合物上烧结金属纳米线（NW）网络是一种新兴的用于制造在多个器件中使用的透明导电电极的方法。脉冲光烧结是一种可扩展的烧结工艺，其中大面积、宽光谱氙灯光引起快速NW融合以增加网络电导率，同时将NW嵌入聚合物中以增加机械鲁棒性。本文发展了一种多物理方法，用于预测在聚碳酸酯上的银纳米线的脉冲光烧结过程中，衬底上的电导率、纳米线熔合和纳米级温度梯度的演变。模型预测成功地验证了实验测得的温度和电阻演变。获得了新的见解到直径依赖的动力学NW融合和纳米级的温度梯度的基板上，这是很难获得实验。这些观察结果也导致理解，NW嵌入在强脉冲光烧结（IPL）可以发生低于聚合物的玻璃化转变温度，并在IPL期间NW嵌入的一个新的差热膨胀为基础的机制。这些见解，以及开发的模型，创建一个框架的物理指导选择的NW，基板和工艺参数，以控制导电性，并防止基板损坏的过程中。
Sintering of metal nanowire (NW) networks on transparent polymers is an emerging approach for fabricating transparent conductive electrodes used in multiple devices. Pulsed light sintering is a scalable sintering process in which large-area, broad-spectrum xenon lamp light causes rapid NW fusion to increase network conductivity, while embedding the NWs in the polymer to increase mechanical robustness. This paper develops a multiphysical approach for predicting evolution of conductivity, NW fusion and nanoscale temperature gradients on the substrate during pulsed light sintering of silver NWs on polycarbonate. Model predictions are successfully validated against experimentally measured temperature and electrical resistance evolution. New insight is obtained into the diameter-dependent kinetics of NW fusion and nanoscale temperature gradients on the substrate, which are difficult to obtain experimentally. These observations also lead to the understanding that NW embedding in intense pulsed light sintering (IPL) can occur below the glass transition temperature of the polymer, and to a new differential thermal expansion-based mechanism of NW embedding during IPL. These insights, and the developed model, create a framework for physics-guided choice of NWs, substrate and process parameters to control conductivity and prevent substrate damage during the process.