Large‐Area Schottky Junctions between ZnO and Carbon Nanotube Fibres

• Published in: ChemPlusChem (Weinheim, Germany) Germany), 2018-04, Vol.83 (4), p.285-293
• Main Authors: Monreal‐Bernal, Alfonso, Vilatela, Juan J.
• Format: Article
• Language: English
• Subjects: carbon; hydrothermal synthesis; interfaces; nanotubes; zinc
• ISSN: 2192-6506; 2192-6506
• DOI: 10.1002/cplu.201700522

In this study, large‐area (10 cm2) samples of heterojunctions between zinc oxide and carbon nanotube (CNT) fibre arrays were synthesised. A two‐step hydrothermal treatment was used to grow Zn nanowires (NWs) in situ directly onto the CNT array. This resulted in a bulk heterojunction that consisted of a five‐micron layer of ZnO crystals in contact with the built‐in CNT fabric current collector, with preferential orientation of the ZnO c axis perpendicular to the CNT sheet. The electrical properties of the heterojunction corresponded to a Schottky junction with a barrier height of 0.26 eV and an ideality factor of 2.9. Photoconductivity measurements indicated charge transfer through the ZnO/CNT interface, thus leading to a gain factor of approximately 100 and a responsivity as high as 5000 mA w−1 under UV irradiation. The resulting ZnO/CNT fibre hybrid was both piezoresistive and piezoelectric under transverse compression with an attractive format for energy‐harvesting applications. Calling the Shottky: Heterojunctions (10 cm2) between ZnO and carbon nanotube (CNT) fiber sheets were synthesized in situ directly onto the CNT array to result in a bulk Schottky junction with a built‐in current collector of CNTs (see figure). Photoconductivity measurements were performed to prove the charge transfer through the interface. The resulting hybrid was shown to be piezoresistive and piezoelectric under transverse compression.