ZnO nanowires as effective luminescent sensing materials for nitroaromatic derivatives

Komla Nomenyo (1) , Roy Aad (1) , Christophe Couteau (1) , Dave J. Rogers (2) , Gilles Lerondel (1)

1 LNIO - Laboratoire de Nanotechnologie et d'Instrumentation Optique
2 Nanovation SARL

We report on the efficient room-temperature photoluminescence (PL) quenching of ZnO in the presence of 2,4-dinitrotoluene (DNT) vapor and for concentration as low as 180 ppb. Compared to ZnO thin films, ZnO nanowires exhibit a strong (95%) and fast (41 s) quenching of the PL intensity in the presence of DNT vapor. Assuming that the PL quenching is due to a trapping of the ZnO excitons by adsorbed DNT molecules, Monte-Carlo calculations show that the nanometric dimensions as well as the better crystallographic quality (longer mean free path) of the ZnO nanowires result in an enhanced trapping process at the origin of the improved sensing properties of the nanowires. The results demonstrate the importance of nanostructures in improving the sensitivity of ZnO. The study also reveals the sensing capability of ZnO nanowires and paves the path towards the potential realization of low-cost sub-ppb nitroaromatic derivative sensors.

Keywords: crystallographic quality; sub-ppb nitroaromatic derivative sensors; nanostructure; nanowire; 2; photoluminescence; quenching; ZnO; ZnO excitons; 4-dinitrotoluene (DNT); nanometric dimension; Monte-Carlo calculations

Domains: Instrumentation and Detectors [physics.ins-det]; Optics / Photonic

Komla Nomenyo, Roy Aad, Christophe Couteau, Dave J. Rogers, Gilles Lerondel. ZnO nanowires as effective luminescent sensing materials for nitroaromatic derivatives. SPIE Optics and Photonics, San Diego Convention Center 2013, Aug 2013, San Diego, United States. ⟨cea-02526328⟩