Patterning of the Surface Electrical Potential on Chalcogenide Glasses by a Thermoelectrical Imprinting Process
Category : Publications | Date : Sep 22, 2020
Ricardo Alvarado, Lara Karam, Redouane Dahmani, Antoine Lepicard, Florian Calzavara, Andréa Piarristeguy, Annie Pradel, hierry Cardinal, Fréderic Adamietz, Evelyne Fargin, Matthieu Chazot, Kathleen Richardson, Luc Vellutini, and Marc Dussauze
J. Phys. Chem. C 2020, 124, 42, 23150–23157
The development of novel sensing systems requires breakthroughs in the conception of multifunctional materials. In this sense, while extensive research has been dedicated to the individual tuning of the electrical or optical properties of different materials, the combination of both features would result in a promising field of research that would further extend opportunities for engineering novel functions in sensor geometries. In the present work, we employed a highly attractive optical material for mid-infrared (MIR) sensing (chalcogenide glasses, ChG) and focused on the spatial control of its surface electrical potential via a thermoelectrical imprinting process. Different glass compositions based on the system Ge–Sb–S–Na were prepared by varying the sulfur stoichiometry and the sodium content. Each glass was thermally poled using electrodes with specific patterns, and subsequent structural modifications and the surface electrical potential were then evaluated via Raman spectroscopy and Kelvin probe force microscopy (KPFM). Raman cartographies show structural modifications attributed to alkali depletion following the patterns of the electrodes used for the imprinting process. Furthermore, KPFM measurements show clearly defined motifs on the electrical potential, which are associated with charges implanted into the glass matrix. It was shown that the surface potential can vary in sign within an amplitude range of 10 V and exhibit patterning at the micrometer scale. We observed that the efficiency of the surface potential imprinted was dramatically impacted by the sulfur and sodium contents of glass. Our results demonstrate for the first time the use of a one-step process, thermal poling, for large-scale patterning of the surface potential of ChG, creating a multifunctional material.
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