Grenoble Alpes University, LMGP, CNRS, F-38000 Grenoble, France.
Nanotechnology. 2017 Feb 3;28(5):055709. doi: 10.1088/1361-6528/28/5/055709. Epub 2016 Dec 29.
Silver nanowire (AgNW) networks are emerging as one of the most promising alternatives to indium tin oxide (ITO) for transparent electrodes in flexible electronic devices. They can be used in a variety of optoelectronic applications such as solar cells, touch panels and organic light-emitting diodes. Recently they have also proven to be very efficient when used as transparent heaters (THs). In addition to the study of AgNW networks acting as THs in regular use, i.e. at low voltage and moderate temperature, their stability and physical behavior at higher voltages and for longer durations should be studied in view of their integration into real devices. The properties of AgNW networks deposited by spray coating on glass or flexible transparent substrates are thoroughly studied via in situ measurements. The AgNW networks' behavior at different voltages for different durations and under different atmospheric conditions, both in air and under vacuum, has been examined. At low voltage, a reversible electrical response is observed while irreversibility and even failure are observed at higher voltages. In order to gain a deeper insight into the behavior of AgNW networks used as THs, simple but realistic physical models are proposed and are found to be in fair agreement with the experimental data. Finally, as the stability of AgNW networks is a key issue, we demonstrate that coating AgNW networks with a very thin layer of TiO using atomic layer deposition (ALD) improves the material's resistance against electrical and thermal instabilities without altering optical transmittance. We show that the critical annealing temperature associated to network breakdown increases from 270 °C for the as-deposited AgNW networks to 420 °C for AgNW networks coated with TiO. Similarly, the electrical failure which occurs at 7 V for the as-deposited networks increases to 13 V for TiO-coated networks. TiO is also proved to stabilize AgNW networks during long duration operation and at high voltage. Temperature higher than 235 °C was achieved at 7 V without failure.
银纳米线（AgNW）网络作为透明电极在柔性电子设备中替代氧化铟锡（ITO）的最有前途的选择之一而出现。它们可用于各种光电应用，例如太阳能电池、触摸面板和有机发光二极管。最近，它们在用作透明加热器（TH）时也被证明非常有效。除了研究 AgNW 网络在常规使用中作为 TH 的行为，即在低电压和中等温度下，还应研究它们在更高电压和更长时间下的稳定性和物理行为，以考虑将它们集成到实际设备中。通过原位测量彻底研究了通过喷涂在玻璃或柔性透明衬底上沉积的 AgNW 网络的性质。研究了 AgNW 网络在不同电压、不同持续时间和不同大气条件下的行为，包括在空气和真空中。在低电压下，观察到可逆的电响应，而在更高电压下则观察到不可逆甚至故障。为了更深入地了解用作 TH 的 AgNW 网络的行为，提出了简单但现实的物理模型，并且发现它们与实验数据吻合良好。最后，由于 AgNW 网络的稳定性是一个关键问题，我们证明使用原子层沉积（ALD）在 AgNW 网络上涂覆非常薄的 TiO 层可以提高材料对电和热不稳定性的抵抗力，而不会改变光透过率。我们表明，与网络击穿相关的临界退火温度从原始 AgNW 网络的 270°C 增加到涂覆 TiO 的 AgNW 网络的 420°C。同样，原始 AgNW 网络在 7V 时发生的电故障增加到涂覆 TiO 的网络的 13V。TiO 还被证明可以在长时间运行和高电压下稳定 AgNW 网络。在 7V 时，温度达到 235°C 以上而没有故障。
