Regensburg 2022 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 18: Oxide Semiconductors (joint session HL/KFM)
HL 18.2: Vortrag
Mittwoch, 7. September 2022, 09:45–10:00, H33
Side-by-side display of optical and resistive H2S gas sensing properties of pristine and gold functionalized ZnO nanowires — •Angelika Kaiser1, Tanja Mauritz1, Joachim Bansmann3, Ulrich Herr1, and Klaus Thonke2 — 1Institute of Functional Nanosystems, University Ulm, 89081 Ulm, Germany — 2Institute of Quantum Matter, Semiconductor Physics Group, University Ulm, 89081 Ulm, Germany — 3Institute for Surface Chemistry and Catalysis, University Ulm, 89081 Ulm, Germany
We investigate the mechanism of hydrogen sulfide (H2S) gas sensing in pristine and gold functionalized zinc oxide (ZnO) nanowires (NW), two potent nanomaterial systems with an enlarged surface-area-to-volume ratio for medical breath analysis in the sub-ppm regime through the "electronic nose" approach. Pristine ZnO NWs (ZnO(NM)) are grown by high-temperature chemical vapor deposition (CVD) and functionalized with gold (Au) nanoparticles by magnetron sputtering (ZnO(Au)). The sensor response is studied by photoluminescence (PL) and electrical conductivity measurements of as-grown ZnO NWs and open gate ZnO NW ChemFET structures. A systematical side-by-side comparison of PL-intensity-time measurements and current-time measurements reveal a two-step detection process between 1 ppm of H2S and ZnO(NM)/ZnO(Au) NWs. Temperature series hints at underlying gas adsorption/desorption processes. Additional X-ray photoelectron spectroscopy (XPS) confirms the beneficial gas-sensitive affinity between Au functionalization and H2S gas, which leads to a significant improvement of the sensitivity for H2S detection.