Researchers have built a thin-film transistor that not only switches current with respectable performance but also glows blue and emits an audible beep when probed by a near-infrared reader, turning the device itself into a built-in anticounterfeiting feature. The work, published in Discover Applied Sciences, combines an eco-friendly graphene oxide chemistry with standard microfabrication steps to produce a multifunctional platform aimed at wearable, smart and secure electronics.
The team, led by Joydeep Biswas, Nisha Naik, Dhruva Kumar, Gunja Prasad, Ashok Rao, Dhananjaya Kekuda and Dhanya Sunil, started with graphene oxide prepared by the modified Hummers method. Instead of using harsh chemical reducing agents, they reduced the graphene oxide with ascorbic acid, a greener route that preserves the material’s usability for printed electronics. They then synthesized a nickel oxide–reduced graphene oxide composite via microwave irradiation. Structural confirmation came from X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy and energy-dispersive spectroscopy, which together verified the composite’s crystal structure, chemical bonding and elemental composition.
With the composite in hand, the researchers formulated a functional screen-printable ink by mixing a commercial phosphor, JUP-AS110, into the NiO/rGO material. The researchers formulated a functional screen-printable ink by mixing the commercial phosphor JUP-AS110 into the NiO/rGO composite, embedding the phosphor directly in the semiconductor ink. The fabricated transistor uses a staggered bottom-gate architecture, with a DC magnetron sputtered TiO2 gate dielectric, a screen-printed NiO/rGO active layer, and thermally evaporated Al source/drain electrodes.
Three deposition methods were combined to complete the device. A titanium dioxide gate dielectric was deposited by DC magnetron sputtering, the screen-printed NiO/rGO composite served as the active channel layer, and aluminum source and drain electrodes were added by thermal evaporation. When tested, the transistor showed n-channel behavior with an on/off current ratio of 1.95 × 10⁶, a field-effect mobility of 0.16 cm²/V·s, and a subthreshold swing of 1.6 V/decade. The high on/off ratio indicates the device can be switched cleanly between conducting and insulating states, a key requirement for digital logic and sensing applications. The reported field-effect mobility was 0.16 cm²/V·s, which the authors present as highlighting the device's potential for low-voltage electronic applications.
The security functionality is where the device departs from conventional thin-film transistors. When excited by a 980 nm laser, the embedded phosphor responds with near-infrared emission that a dedicated IR taggant reader detects as blue emission at 475 nm. The same reader produces an audible beep, giving the verification process both a visual and an acoustic output. In response to near-infrared emission under 980 nm laser excitation, the device exhibited blue emission at 475 nm along with an audible beep using an IR taggant reader, giving the verification process both a visual and an acoustic output.
Anticounterfeiting architectures built on thin-film transistors promise scalable, flexible and cost-effective protection against product forgery, according to the authors. According to the authors, TFT-based anticounterfeiting architectures promise scalable, flexible and cost-effective protection against product forgery, and TFTs have evolved from display backplanes to printed, transparent and conformal forms. The phosphor was mixed into the screen-printable NiO/rGO ink used for the active layer, integrating the security feature into the semiconductor material itself.
The choice of materials also reflects a sustainability angle. The graphene oxide was reduced using ascorbic acid, which the authors describe as an eco-friendly reduction route. The NiO/rGO composite was synthesized via microwave irradiation, an approach the authors list among the study's eco-friendly processing choices. The gate dielectric was DC magnetron sputtered titanium dioxide. The authors highlight the eco-friendly reduction of graphene oxide and the microwave-assisted synthesis of the NiO/rGO composite as key contributions of the study.
The transistor also exhibited a subthreshold swing of 1.6 V/decade, one of the device parameters the authors report alongside the on/off ratio and mobility. Combined with the high on/off ratio, the device parameters suggest the platform could serve low-voltage, high-performance electronic applications while simultaneously providing the anticounterfeiting function. The authors highlight the eco-friendly reduction of graphene oxide, the microwave-assisted synthesis of the composite, the phosphor-integrated screen ink formulation, and the built-in security functions as the study’s key contributions.
The study combines device fabrication, sustainable materials processing and built-in security functions in a single thin-film transistor platform. The built-in security features, including the blue emission and audible beep in response to near-infrared excitation, are presented by the authors as enabling multifunctional anticounterfeiting capabilities. The authors state that the results confirm the platform's promise as a multifunctional smart, sustainable and secure platform for advanced anticounterfeiting applications.
Subject of Research: A sustainable thin-film transistor platform with integrated optical and acoustic anticounterfeiting features for smart electronics.
Article Title: Sustainable and secure thin-film transistor platform with integrated optical–acoustic anticounterfeiting features for smart electronics
Article References: Biswas, J., Naik, N., Kumar, D., Prasad, G., Rao, A., Kekuda, D., & Sunil, D. (2026). Sustainable and secure thin-film transistor platform with integrated optical–acoustic anticounterfeiting features for smart electronics. Discover Applied Sciences. https://doi.org/10.1007/s42452-026-09845-x
Image Credits: AI Generated
DOI: 10.1007/s42452-026-09845-x
Keywords: thin-film transistor, graphene oxide, anticounterfeiting, NiO/rGO composite, screen printing, phosphor, near-infrared, sustainable electronics, microwave synthesis, titanium dioxide dielectric, printed electronics, device security
News Source: Neil Sanderson. (November 9, 2026). Graphene oxide transistor doubles as a talking anticounterfeiting tag. Scienmag.
