Preparation and Characterization of Sodium-Containing Germanium Selenide Amorphous Thin Films

Flammable, organic liquid electrolytes used in rechargeable lithium-ion batteries are a safety concern in power storage applications. Moreover, lithium is expensive; its resources are limited and abundant in politically sensitive areas. Increasing demand for large-capacity, rechargeable power storage devices in electric vehicles requires safe, low-cost, all-solid-state batteries which would prevent leakage, volatilization, and flammability of electrolytes. Rechargeable sodium-ion batteries satisfy these with appropriate materials for cathode and solid-state electrolytes. GeSe glasses are good candidates for such application. In present work, amorphous thin films of Na-containing GeSe have been prepared using thermal evaporation in vacuum method. These films are characterized with scanning electron microscopy and impedance spectroscopy. Electrical characterization was performed from 4 Hz to 8 MHz frequencies using HIOKI LCR meter and temperature controlled LINKAM stage. Temperature and frequency dependences of measured electrical parameters were used to calculate Cole-Cole dependencies. The possibility to use this material as solid-state electrolyte for sodium transport is discussed.