Graphene functionalised by laser-ablated V 2 O 5 for a highly sensitive NH 3 sensor

• Published in: Beilstein journal of nanotechnology Vol. 8; pp. 571 - 578
• Main Authors: Kodu, Margus, Berholts, Artjom, Kahro, Tauno, Kook, Mati, Ritslaid, Peeter, Seemen, Helina, Avarmaa, Tea, Alles, Harry, Jaaniso, Raivo
• Format: Journal Article
• Language: English
• Published: Germany 07.03.2017
• Subjects: UV light activation; pulsed laser deposition; ammonia; gas sensor; vanadium(V) oxide; electric conductivity; graphene
• ISSN: 2190-4286; 2190-4286
• DOI: 10.3762/bjnano.8.61

Graphene has been recognized as a promising gas sensing material. The response of graphene-based sensors can be radically improved by introducing defects in graphene using, for example, metal or metal oxide nanoparticles. We have functionalised CVD grown, single-layer graphene by applying pulsed laser deposition (PLD) of V O which resulted in a thin V O layer on graphene with average thickness of ≈0.6 nm. From Raman spectroscopy, it was concluded that the PLD process also induced defects in graphene. Compared to unmodified graphene, the obtained chemiresistive sensor showed considerable improvement of sensing ammonia at room temperature. In addition, the response time, sensitivity and reversibility were essentially enhanced due to graphene functionalisation by laser deposited V O . This can be explained by an increased surface density of gas adsorption sites introduced by high energy atoms in laser ablation plasma and formation of nanophase boundaries between deposited V O and graphene.