Dresden 2017 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 64: Poster: Photovoltaics and Optics

HL 64.2: Poster

Wednesday, March 22, 2017, 15:00–19:00, P1C

Charge storage in β-FeSi₂ nanoparticles — •Fangfei Li¹, Martin Geller¹, Hans Orthner², Jens Theis¹, Hartmut Wiggers², and Axel Lorke¹ — ¹Experimental Physics and CENIDE, University of Duisburg-Essen, Germany — ²Institute for Combustion and Gas Dynamics and CENIDE, University of Duisburg-Essen, Germany

Especially, for mobile electronics, rechargeable batteries or supercapacitors with high capacities and energy density are needed. Nanomaterials can fulfill this demand because of their large specific surface area, providing space for electrochemical reactions.

In our research, a capacitor with non-toxic, semiconducting β-FeSi₂ nanoparticles shows a relatively high capacity, which points towards a yet unexplored potential of β-FeSi₂ nanoparticles in energy storage technologies. The β-FeSi₂ capacitor does not require an electrolyte and operates under ambient conditions. However, its capacitance is quite sensitive to solvents in the gaseous atmosphere (i.e. water, acetone) and humidity. With increasing relative humidity, the capacitance increases exponentially. Compared to the bare electrodes without β-FeSi₂ nanoparticles, the β-FeSi₂ nanoparticles-coated samples exhibit an up to 3−4 orders of magnitude increased capacitance. Time-resolved current-voltage measurements show that for a short time after the charging pulse (seconds to minutes), the capacitance on average reaches 2.5 As/g at a charging voltage of 3V. Moreover, the devices are robust, show almost no degradation under ambient conditions, and can still be used after months of storage and repeated measurements.