UV-Responsive Screen-Printed Porous ZnO Nanostructures on Office Paper for Sustainable and Foldable Electronics

Abstract

The fabrication of low-cost, flexible, and recyclable electronic devices has been the focus of many research groups, particularly for integration in wearable technology and the Internet of Things (IoT). In this work, porous zinc oxide (ZnO) nanostructures are incorporated as a UV sensing material into the composition of a sustainable water-based screen-printable ink composed of carboxymethyl cellulose (CMC). The formulated ink is used to fabricate flexible and foldable UV sensors on ubiquitous office paper. The screen-printed CMC/ZnO UV sensors operate under low voltage (≤2 V) and reveal a stable response over several on/off cycles of UV light exposure. The devices reach a response current of 1.34 ± 0.15 mA and a rise and fall time of 8.2 ± 1.0 and 22.0 ± 2.3 s, respectively. The responsivity of the sensor is 432 ± 48 mA W−1, which is the highest value reported in the literature for ZnO-based UV sensors on paper substrates. The UV-responsive devices display impressive mechanical endurance under folding, showing a decrease in responsivity of only 21% after being folded 1000 times. Their low-voltage operation and extreme folding stability indicate a bright future for low-cost and sustainable flexible electronics, showing potential for low-power wearable applications and smart packaging.

Freestanding Translucent ZnO–Cellulose Nanocomposite Films for Ultraviolet Sensor Applications

“…The maximum values of R and S were 36.5 mA/W and 247, respectively, for the device with a gap of 75 μm. Compared to previously reported devices in which ZnO nanostructures were deposited on Whatman paper [ 18 ], our device showed three orders of magnitude larger responsivity, with similar sensitivity. Moreover, compared to previously reported devices in which a ZnO/CMC composite layer was deposited on copy paper, our device showed 18 times larger sensitivity.…”

“…The higher responsivity and sensitivity of our nanocomposite films compared with those reported previously could be attributed to the short interelectrode distance. The interelectrode distance of 75 μm, which is shorter than that in previous studies [ 13 , 18 , 19 ], may have reduced the scattering of photoexcited carriers at the ZnO NP interface during their transport.…”

“…However, the responsivities (0.39–1.20 μA/W) were relatively lower than those of the first type of devices. The third structure is a hybrid of the first and second structures [ 18 ], in which a composite film of ZnO nanostructures and carboxymethyl cellulose is deposited on a copy paper by screen printing. This type of device has both good responsivity (432 mA/W) and mechanical flexibility.…”

A Study to Improve the Performance of Mixed Cation–Halide Perovskite-Based UVC Photodetectors

“…When fabricating a UVC photodetector, it is necessary to consider whether a low-temperature and simple process is possible. This is because it is essential to develop sustainable electronic devices to reduce the impacts on the environment of energy consumption and waste [ 15 , 16 ]. Low energy processes make it possible to produce more eco-friendly devices [ 17 ].…”

Visible Photoluminescent Zinc Oxide Nanorods for Label-Free Nonenzymatic Glucose Detection

“…There are several reports of the use of ZnO in sensing applications, including gas sensors, , ultraviolet (UV) sensors, ,, and pressure sensors . Moreover, ZnO is used in applications related to its photocatalytic activity. , In the area of nanomaterials-based glucose sensors, there are several reports of the use of ZnO nanomaterials and hybrid nanostructures containing this metal oxide in enzymatic glucose sensors − and nonenzymatic sensors, whether amperometric − or optical. ,, …”