Dresden 2014 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 44: ZnO and its relatives: Devices

HL 44.7: Vortrag

Dienstag, 1. April 2014, 12:15–12:30, POT 151

ZnO nanowires for gas sensing applications — •Manfred Madel, Julian Jakob, Martin Dickel, Florian Huber, Bruno Amann, and Klaus Thonke — Institute of Quantum Matter / Semiconductor Physics Group, University of Ulm

ZnO nanowires with average diameter of 50−100   nm were grown by chemical vapour deposition. Due to the large surface to volume ratio the nanowires show very good sensing behaviour to adsorbed molecules in different gas atmospheres. Besides conventional electrical measurements, micro-photoluminescence (µ PL) and photoconductivity read out is used for the detection of oxygen atmosphere.
To adress single nanowires in µ PL measurements, these were aligned by the simple and low cost dielectrophoresis method. In our experiments, we find a relationship between sensing behaviour and nanowire form and diameter.
Electrical photoconductivity measurements on dense ensembles of aligned ZnO nanowires on gold contacts show that the decay time of the electrical current after switching off UV illumination depends stronlgy on the ambient gas atmosphere.
For both methods the detection limit for oxygen was found to be in the lower ppm range.