Dresden 2026 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 16: Functional Materials II

MM 16.3: Talk

Tuesday, March 10, 2026, 14:30–14:45, SCH/A216

In-Situ Activation of a Monolithic SrTiO3 Single Crystal for Room Temperature Hydrogen Sensing — •Karl-Michael Weitzel, Timo Kassubek, and Kevin Rein — Department of Chemistry, Philipps-Universität Marburg, Marburg, Germany

The development of reliable, fast, and cost-effective hydrogen sensors is of increasing importance for the safe implementation of a hydrogen-based economy. This work presents a novel and simple single-step method to convert an insulating strontium titanate (SrTiO3) single crystal into a highly sensitive, monolithic hydrogen sensor that operates at room temperature. The activation is achieved by applying a moderate DC electric field (100 V/cm) across a symmetric Pt/SrTiO3/Pt capacitor structure at 180 °C in a pure hydrogen atmosphere (200 mbar). This process causes a drastic and stable reduction in the material's resistance by several orders of magnitude. We propose a model of "field-induced chemical doping" to explain this transformation. The resulting activated crystal exhibits excellent hydrogen sensing properties at room temperature, detecting molecular hydrogen (H2) over an exceptionally wide partial pressure range from 0.0001 mbar to 1000 mbar with an accuracy of a few percent. The sensing mechanism is based on the reaction of hydrogen with the activated SrTiO3 sample, involving the release of electrons back into the conduction band and lowering the device's resistance. This monolithic approach opens a new pathway for designing robust and easy-to-fabricate chemical sensors from wide-bandgap oxides.

Keywords: Electrochemical Activation; Electrical Conductivity; Hydrogen Sensor