Sustainable Fully Printed UV Sensors on Cork Using Zinc Oxide/Ethylcellulose Inks

Area of Science:

• Materials Science
• Electronics Engineering
• Nanotechnology

Background:

• Flexible electronics production is advancing for wearable tech and IoT.
• Screen-printing offers a low-cost, scalable method for device fabrication.

Purpose of the Study:

• To demonstrate fully screen-printed UV photodetectors on a sustainable cork substrate.
• To evaluate the performance and stability of these photodetectors for potential wearable applications.

Main Methods:

• Fabrication of UV photodetectors using a mixture of zinc oxide nanoparticles and ethylcellulose as the active layer.
• Low-temperature screen-printing on a cork substrate.
• Characterization of photoresponse, dark current, response times, and mechanical stability under bending stress.

Main Results:

• The UV photodetectors exhibited a quasi-quadratic photoresponse proportional to applied voltage (302 nm UV source).
• Photocurrent reached ~5.5 μA at 1.5 V and ~20 μA at 5 V, with dark current below 150 nA.
• Fast response times (<5 s rise, <2 s fall) and stable operation with only 9% degradation after 100 bending cycles (45 mm radius).

Conclusions:

• Screen-printed UV photodetectors on cork are feasible, low-cost, and demonstrate promising performance.
• The flexibility and stability of these sensors make them suitable for integration into wearable devices like hats, bracelets, and bags.
• This work highlights the potential of sustainable materials and additive manufacturing for next-generation electronic sensors.