title: A near single crystalline TiO2 nanohelix array: enhanced gas sensing performance and its application as a monolithically integrated electronic nose.
abstract: We present high performance gas sensors based on an array of near single crystalline TiO(2) nanohelices fabricated by rotating oblique angle deposition (OAD). The combination of large surface-to-volume ratio, extremely small size (<30 nm) comparable to the Debye length, a near single crystallinity of TiO(2) nanohelices, together with the unique top-and-bottom electrode configuration hugely improves the H(2)-sensing performance, including ∼10 times higher response at 50 ppm, approximately a factor of 5 lower detection limit, and much faster response time than the conventional TiO(2) thin film devices. Beyond such remarkable performance enhancement, the excellent compatibility of the OAD method compared with the conventional micro-fabrication technology opens a new avenue for monolithic integration of high-performance chemoresistive sensors to fabricate a simple, low cost, reliable, yet fully functional electronic nose and multi-functional smart chips for in situ environmental monitoring.
authors.affiliation: Department of Materials Science and Engineering, POSTECH, Pohang 790-784, Republic of Korea.
authors.forename: Sunyong
authors.initials: S
authors.lastname: Hwang
authors.forename: Hyunah
authors.initials: H
authors.lastname: Kwon
authors.forename: Sameer
authors.initials: S
authors.lastname: Chhajed
authors.forename: Ji Won
authors.initials: JW
authors.lastname: Byon
authors.forename: Jeong Min
authors.initials: JM
authors.lastname: Baik
authors.forename: Jiseong
authors.initials: J
authors.lastname: Im
authors.forename: Sang Ho
authors.initials: SH
authors.lastname: Oh
authors.forename: Ho Won
authors.initials: HW
authors.lastname: Jang
authors.forename: Seok Jin
authors.initials: SJ
authors.lastname: Yoon
authors.forename: Jong Kyu
authors.initials: JK
authors.lastname: Kim
mesh_terms: D015374:Biosensing Techniques; D062609:Electronic Nose; D005740:Gases / Q000032:analysis* / Q000737:chemistry; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation; D009812:Odorants / Q000032:analysis; D014025:Titanium / Q000737:chemistry*
chemical_list: D005740:Gases; C009495:titanium dioxide; D014025:Titanium