Berlin 2018 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 37: Oxide Semiconductors

HL 37.2: Talk

Thursday, March 15, 2018, 09:45–10:00, EW 203

Controlling and Analyzing the Conductivity of TiO2 Nanorod Arrays — •Carola Ebenhoch, Julian Kalb, Elise Sirotti, Domenik Vögel, and Lukas Schmidt-Mende — Department of Physics, University of Konstanz, Germany

Besides being an important semiconducting material in industry for electrical components such as transistors, diodes, sensors, solar cells, and many more [1], TiO2 can easily be grown in nanometer dimensions (e.g. thin films via SALD and nanowires via hydrothermal growth), which enables the access to nanodevices. Due to an increased surface to bulk ratio for nanowires, effects from surface states become even more important for electronic properties, which still require extensive investigations. In this regard, we present conductivity measurements on nanorod arrays grown on a FTO substrate via hydrothermal growth, contacted with a gold tip as top electrode. The density of defect states at the surface, e.g. oxygen vacancies, were modified using a post annealing process in different atmospheres. With this method, temperature dependent conduction mechanisms for highly conductive nanowires, containing a large amount of oxygen vacancies at the surface [2], or rather low conductive nanowires could be identified.

[1] Yu, X., et al., Metal oxides for optoelectronic applications. Nat Mater, 2016. 15(4): p. 383-96.

[2] Folger, A., et al., Tuning the Electronic Conductivity in Hydrothermally Grown Rutile TiO(2) Nanowires: Effect of Heat Treatment in Different Environments. Nanomaterials (Basel), 2017. 7(10).