NovaCentrix Silver Inks Drive Scalable, Eco-Friendly Near-Infrared Photodetectors
The field of printed electronics continues to push the boundaries of device functionality and manufacturing sustainability. A recent publication in Advanced Materials Technologies by Jenner H. L. Ngai, Zhao Li, Jianfu Ding, and Yuning Li showcases a compelling advancement: high-performance, printed p-n junction thin-film near-infrared (NIR) photodetectors. This innovative work leverages the precision and versatility of microplotter printing, with NovaCentrix silver inks playing a crucial role in fabricating the essential conductive electrodes that underpin these devices. The research highlights a path toward scalable, low-power, and environmentally friendly NIR sensing solutions, addressing critical needs in diverse applications from environmental monitoring to optical communication.
At the heart of these next-generation photodetectors is a sophisticated bilayer architecture combining chirality-enriched single-walled carbon nanotubes (SWCNTs) with a sustainable furan-derived π-conjugated polymer (PFEB). This unique pairing facilitates efficient exciton dissociation and charge transport, leading to significantly enhanced NIR detection performance. The ability to precisely deposit both the active materials and the conductive electrodes through printing techniques is paramount to achieving the scalability and cost-effectiveness required for widespread adoption.
Why This Matters: Advancing NIR Sensing with Sustainable Printed Electronics
Near-infrared photodetectors are vital components in a wide array of technologies, including medical diagnostics, environmental sensing, night vision, and optical communication. Traditional NIR photodetectors often rely on complex, energy-intensive fabrication methods that limit their scalability and increase costs. There is a growing demand for devices that are not only high-performing but also sustainable, low-power, and compatible with flexible substrates, enabling new form factors and applications.
This research directly addresses these challenges by demonstrating a fully printed device architecture that utilizes a bio-derived polymer and green solvents, aligning with broader sustainability goals in optoelectronics. The successful integration of advanced materials with scalable printing techniques, such as microplotter printing, is a significant step toward realizing the next generation of flexible, disposable, and environmentally conscious NIR sensors. The precision offered by these printing methods, coupled with high-quality conductive inks, is critical for achieving the necessary device performance.
The Role of NovaCentrix Silver Inks in Electrode Fabrication
The functionality and performance of any printed electronic device are intrinsically linked to the quality and characteristics of its conductive components. In this study, NovaCentrix silver inks were instrumental in the fabrication of the electrodes for the SWCNT-based photodetectors. Researchers employed picoliter-scale microplotter printing to dispense both aqueous and anisole-based silver inks, forming the conductive pathways for the devices.
The use of NovaCentrix silver inks for these electrodes offers several key advantages. Firstly, the inks are formulated for precise deposition via inkjet and microplotter printing, enabling the creation of intricate electrode geometries without the need for expensive photolithography or vacuum processing. Secondly, the excellent conductivity of the sintered silver traces ensures efficient charge collection from the active SWCNT/polymer layers. The versatility of NovaCentrix’s inkjet conductive inks, including aqueous formulations like JS-A010ET silver nanoparticle ink, allows researchers to select materials optimized for their specific printing processes and substrate requirements, whether rigid SiO₂ or flexible PET and PI.
Device Architecture and Performance Highlights
The fabricated photodetectors feature a lateral resistor-type architecture, where the p-n junction is formed by the bilayer of PFEB (p-type semiconductor) and chirality-sorted (10,9)-enriched SWCNTs (electron acceptor). The electrodes, precisely printed with NovaCentrix silver inks, provide the necessary electrical contacts for the active layers. The study investigated devices on various substrates, including rigid SiO₂ and flexible PET and PI, demonstrating the adaptability of the printing approach.
- High External Quantum Efficiency (EQE): The best rigid device on SiO₂ achieved an EQE of 19.7% at 1000 nm.
- Excellent Responsivity (R): This device also exhibited a responsivity of 0.159 A/W at 1000 nm.
- Superior Specific Detectivity (D*): A specific detectivity of 2.66 × 10⁸ Jones was recorded at 1000 nm for the rigid device.
- Flexible Device Performance: A fully printed flexible device on PI achieved an EQE of 6.47%, R of 0.0522 A/W, and D* of 7.90 × 10⁷ Jones at 1000 nm, showcasing robust performance on flexible substrates.
- Enhanced Photoresponse: Thermal annealing at 250°C, which cleaves carbamate side chains from PFEB to yield PFNB, significantly enhanced the ~1000 nm photoresponse by improving interfacial contact and strengthening intermolecular coupling between the polymer and SWCNTs.
These impressive metrics, particularly for printed devices, underscore the effectiveness of the material combination and the precision of the printing process enabled by high-quality conductive inks. The ability to achieve such performance on both rigid and flexible substrates opens up a wide range of potential applications.
Sustainability and Scalability in Printed Optoelectronics
Beyond the high performance, a key aspect of this research is its commitment to sustainability. The PFEB polymer is synthesized from furfural, a renewable feedstock, via a short and efficient route. Furthermore, the polymer is solution-processable in green solvents like anisole. This, combined with the additive manufacturing nature of microplotter printing, represents a significantly more environmentally friendly and scalable fabrication process compared to traditional semiconductor manufacturing.
The ability to print these devices using readily available, sustainable materials and processes, with NovaCentrix inks providing the conductive backbone, paves the way for mass production of low-cost, disposable, and flexible NIR photodetectors. This approach minimizes material waste, reduces energy consumption, and avoids hazardous chemicals often associated with conventional fabrication, marking a significant step forward for green electronics.
Looking Ahead: The Future of Printed NIR Sensing
This study by Ngai et al. provides a strong foundation for the future development of fully printed optoelectronic devices. The demonstrated polymer/SWCNT platform, enabled by the precise deposition of NovaCentrix conductive inks, offers a versatile and promising route for creating advanced NIR sensors. Future work will undoubtedly focus on further optimizing ink formulations, printing parameters, and material combinations to achieve even higher performance, greater spectral coverage, and improved device-to-device uniformity.
At NovaCentrix, we are proud to support cutting-edge research that pushes the boundaries of what’s possible with printed electronics. Our commitment to developing high-performance, reliable conductive inks empowers researchers to innovate and create solutions for critical global challenges. We look forward to seeing how this work will inspire further advancements in sustainable, scalable, and high-performance printed optoelectronics.
Read the full paper: Ngai, J. H. L.; Li, Z.; Ding, J.; Li, Y. Printed SWCNT-Based p-n Junction Thin-Film Near-Infrared Photodetectors Enabled by a Sustainable Furan-Derived π-Conjugated Polymer. Advanced Materials Technologies 2026, e71185. DOI: 10.1002/admt.71185