Patil Jatin J, Reese Maya L, Lee Eric, Grossman Jeffrey C
Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
ACS Appl Mater Interfaces. 2022 Jan 26;14(3):4423-4433. doi: 10.1021/acsami.1c20521. Epub 2022 Jan 14.
Silver nanowire (AgNW) networks have been explored as a promising technology for transparent electrodes due to their solution-processability, low-cost implementation, and excellent trade-off between sheet resistance and transparency. However, their large-scale implementation in applications such as solar cells, transparent heaters, and display applications has been hindered by their poor thermal, electrical, and chemical stability. In this work, we present reactive sputtering as a method for fast deposition of metal oxynitrides as an encapsulant layer on AgNWs. Because O cannot be used as a reactive gas in the presence of oxidation-sensitive materials such as Ag, N is used under moderate sputtering base pressures to leverage residual HO on the sample and chamber to deposit Al, Ti, and Zr oxynitrides (AlON TiON, and ZrON) on Ag nanowires on glass and polymer substrates. All encapsulants improve AgNW networks' electrical, thermal, and chemical stability. In particular, AlON-encapsulated networks present exceptional chemical stability (negligible increase in resistance over 7 days at 80% relative humidity and 80 °C) and transparency (96% for 20 nm films on AgNWs), while TiON demonstrates exceptional thermal and electrical stability (stability up to over temperatures 100 °C more than that of bare AgNW networks, with a maximum areal power density of 1.72 W/cm, and no resistance divergence at up to 20 V), and ZrON presents intermediate properties in all metrics. In summary, a novel method of oxynitride deposition, leveraging moderate base pressure reactive sputtering, is demonstrated for AgNW encapsulant deposition, which is compatible with roll-to-roll processes that are operated at commercial scales, and this technique can be extended to arbitrary, vacuum-compatible substrates and device architectures.
由于银纳米线（AgNW）网络具有可溶液加工性、低成本实现以及在薄层电阻和透明度之间的出色权衡，因此已被探索作为一种用于透明电极的有前景的技术。然而，它们在太阳能电池、透明加热器和显示应用等领域的大规模应用受到其较差的热稳定性、电稳定性和化学稳定性的阻碍。在这项工作中，我们提出了反应溅射法，作为一种在AgNWs上快速沉积金属氮氧化物作为密封层的方法。由于在存在诸如Ag等对氧化敏感的材料时不能使用O作为反应气体，因此在适度的溅射基础压力下使用N，以利用样品和腔室中的残余HO在玻璃和聚合物基板上的Ag纳米线上沉积Al、Ti和Zr的氮氧化物（AlON、TiON和ZrON）。所有密封剂都提高了AgNW网络的电稳定性、热稳定性和化学稳定性。特别是，AlON封装的网络具有出色的化学稳定性（在80%相对湿度和℃下7天内电阻增加可忽略不计）和透明度（AgNWs上20nm薄膜的透明度为96%），而TiON表现出出色的热稳定性和电稳定性（在超过100℃的温度下比裸AgNW网络的稳定性高，最大面功率密度为1.72W/cm，在高达20V时无电阻发散），并且ZrON在所有指标上表现出中等性能。总之，展示了一种利用适度基础压力反应溅射的氮氧化物沉积新方法，用于AgNW密封剂沉积，该方法与商业规模运行的卷对卷工艺兼容，并且该技术可以扩展到任意的、与真空兼容的基板和器件架构。
