Flexible Carbon Nanotube Hybrid Paper Has Efficient UV Sensing, Photocatalyst Applications
Using zinc oxide (ZnO), researchers at the NSF-funded Lighting Enabled Systems & Applications ERC (LESA), headquartered at Rensselaer Polytechnic University, have fabricated a flexible, carbon nanotube (CNT) hybrid paper with high aspect ratio for efficient ultraviolet (UV) sensing and photocatalyst applications.
This method may open up opportunities to fabricate many other flexible, recyclable and high-performance functional devices. UV photodetectors are used to secure space-to-space communications, pollution monitoring, water sterilization, flame sensing, and early missile plume detection, and can play an important role in purifying air and water containing low concentrations of pollutants.
While GaN is the most common and well commercialized wide-band gap material for ultraviolet devices, ZnO has drawn significant research interest due to its unique optical and electronic properties, including wide band-gap, large exciton binding energy at room temperature, low cost, and environmental friendliness.
A ZnO-multi-wall CNT (MWCNT) hybrid paper was fabricated via atomic layer deposition on the outside surface of the MWCNT followed by hydrothermal growth of ZnO branches, achieving a very high surface-to-volume ratio. A photodetector fabricated from the hybrid paper demonstrates a very high photo-responsivity and a fast transient response in the UV region.