Photonic post-processing of a multi-material transparent conductive electrode architecture for optoelectronic device integration

• Published in: RSC advances 2024-01, Vol.14 (7), p.4748-4758
• Main Authors: Gerlein, Luis Felipe, Benavides-Guerrero, Jaime Alberto, Cloutier, Sylvain G
• Format: Article
• Language: English
• Subjects: Carrier transport; Chemistry; Current carriers; Electrodes; Low temperature; Metal oxides; Nanowires; Optoelectronic devices; Photonics; Polyethylene terephthalate; Silver; Sintering; Substrates; Titanium; Titanium dioxide
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d3ra07103k

Emerging flexible optoelectronic devices require multi-material processing capabilities to fully enable the use of temperature-sensitive substrates and materials. This report demonstrates how photonic sintering enables the processing of materials with very different properties. For example, charge carrier transport/blocking metal-oxides, and transparent conductive silver nanowire-based electrodes ought to be compatible with low-energy and high-throughput processing for integration onto flexible low-temperature substrates. Compared to traditional post-processing methods, we show a rapid fabrication route yielding highly-stable hybrid electrode architectures on polyethylene terephthalate (PET). This architecture consists of an interconnected silver nanowire network encapsulated with a thin crystalline photo-sensitive titanium dioxide (TiO 2 ) coating, allowing both layers to be treated using independent photonic post-processing sintering steps. The first step sinters the nanowires, while the second completes the conversion of the top metal-oxide layer from amorphous to crystalline TiO 2 . This approach improves on the fabrication speed compared to oven processing, while delivering optical and electrical characteristics comparable to the state of the art. Optimized transparency values reach 85% with haze values down-to 7% at 550 nm, while maintaining a sheet resistance of 18.1 Ω sq. −1 . However, this hybrid architecture provides a much stronger resilience to degradation, which we demonstrate through exposure to harsh plasma conditions. In summary, this study shows how carefully-optimized photonic curing post-processing can provide more-stable hybrid architectures while using a multi-material processing technique suitable for high-volume manufacturing on low-temperature substrates. Photonic postprocess of multimaterial, highly conductive transparent electrodes. Separate annealing of AgNWs and crystallization of a TiO 2 layer atop are proved. This novelty processing results in two opposing types of materials: nanowires and titania being transformed atop a PET substrate.