• Nguyen, Viet Hung
• Bardet, Laetitia
• Crivello, Chiara
• Akbari, M.
• Bellet, Daniel
• Papanastasiou, Dorina Theodora
• Sekkat, A.
• Munoz-Rojas, David
• Jiménez, Carmen
• Denneulin, Aurore
• Resende, J.
• Sanchez-Velasquez, Camilo

Abstract

Transparent electrodes (TE) are essential components in a huge variety of emerging applications such as photovoltaic, lighting, sensing and heating devices.[1,2] Indium tin oxide (ITO) has been the most efficient and widely used TE but suffers from serious limitations related to fabrication cost, brittleness and indium scarcity.[3] Among emerging transparent conductive materials (TCMs), metallic nanowire (MNW) networks, and especially silver nanowire (AgNW) networks, appear to be one of the most promising alternatives to ITO, since: i/ they exhibit excellent optical and electrical properties, ii/ they are very flexible, and iii/ they can be fabricated by low-cost, solution-based techniques suitable for large scale, industrial production.[4] Despite the advantages mentioned above, to build a robust and mature technology, there are still challenges to be tackled. Stability is a crucial issue that can be attributed to several degradation mechanisms involving electrical, thermal and mechanical aspects, ageing and chemical degradation.[5] Our present study focuses on the fundamental understanding of the physical phenomena that take place at different scales, from the whole network (macroscale) to the nanowire-to-nanowire junctions (nanoscale). Combining both experimental and modelling approaches, one of the main goals aims to understand the origin of failure in AgNW networks during electrical stress. In situ measurements of the electrical resistance with a parallel recording of the spatial surface temperature by IR imaging have yielded useful information about the failure dynamics of AgNW networks.[6] The simulation of the electrical distribution and power-induced heating offer a deeper understanding of the underlying physics and can be used to predict the networks electrical and heating performances.[7] Moreover, we observe the drastic enhancement of the electrical and thermal stability when we encapsulate the AgNWs networks with protective oxides such as ZnO, Al: ZnO (AZO) and Al2O3, using the Spatial Atomic Layer Deposition (SALD). This emerging open air, low-cost and scalable approach enables the deposition of ultrathin, high conformal and transparent oxide coatings at low temperatures.[8–10] Such work represents both fundamental and applicative aspects. For the latter, one aims to integrate AgNW based TE for instance in solar cells, transparent heaters, low-emissivity coating and energy harvesting devices.

Topics

• impedance spectroscopy
• surface
• silver
• simulation
• aging
• tin
• Indium
• atomic layer deposition