Engineering junction contact states for selective Joule sintering and current distribution control in flexible silver nanowire electrodes

Abstract

Silver nanowire (AgNW) networks are promising electrode candidates for flexible organic solar cells (FOSCs) due to their outstanding optoelectronic properties and mechanical flexibility. However, their practical deployment remains hindered by high junction resistance and inherent surface irregularities, which lead to non-uniform current distribution and increased energy dissipation. Here, we report a hyaluronic acid (HA)-assisted Joule-heating strategy that enables spatially uniform yet junction-selective sintering within AgNWs. The HA treatment increases the density of effective inter-nanowire contacts and improves interfacial adhesion, thereby preconditioning the network for a more homogeneous current distribution. As a result, Joule heating is preferentially localized at electrically active junctions, leading to efficient welding without damaging the overall network. This synergistic regulation produces AgNW electrodes with reduced sheet resistance, improved surface smoothness, and enhanced mechanical robustness, while preserving high optical transparency. Based on the transition from localized current crowding to a homogenized transport regime, which contributes to reduced resistive losses and suppressed recombination, the FOSCs achieve a power conversion efficiency increased from 16.85% to 18.09%, which is the highest reported value of inverted FOSCs. This work establishes a general strategy for coupling network densification with electrically driven selective sintering, offering a scalable route toward high-performance transparent electrodes for next-generation flexible optoelectronics.

Keywords

Silver nanowires / Joule heating / flexible transparent electrodes / organic solar cells

Acknowledgements

The authors would like to acknowledge the experimental support provided by the Collaborative Innovation Center of Suzhou Nano Science & Technology. The authors confirm that Gemini was used to assist the language polishing and grammar checking of this paper. The authors have reviewed and take full responsibility for all content of the final manuscript.

Authors contribution

Khan MS, Deng ZY, Zhang JL: Investigation, validation. Wen C: Writing-original draft, formal analysis. Chen JD, Li YQ, Tang JX: Conceptualization, supervision, writing-review & editing. Ren H: Investigation. Zhou SJ: Validation.

Conflicts of interest

Jing-De Chen serves as a Young Editor and Jian-Xin Tang serves as an Editorial Board Member of Smart Materials and Devices. The other authors declare no conflicts of interest.

Ethical approval

Not applicable.

Consent to participate

Not applicable.

Consent for publication

Not applicable.

Availability of data and materials

The data and materials supporting the findings of this study are available from the corresponding author upon reasonable request.

Funding

The authors acknowledge the financial support from the National Natural Science Foundation of China (Nos. U23A20371, T2425024, 62320106004, 62275181), the Science and Technology Development Fund (FDCT), Macau (No. 0008/2022/AMJ), the Bureau of Science and Technology of Suzhou Municipality (No. SYC2022144).

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