Synthesis of Chalcogenide Glasses
Semiconducting chalcogenide glasses are fascinating materials with important applications in phase-change memory, nanoionic memristive memory, radiation sensing, gas sensing, optical storage, and microfluidics.
Chalcogenide glasses contain sulfur, selenium and/or tellurium. Combined with a variety of other elements, these three chalcogens form a large family of semiconducting glasses with band gaps ranging from 1 to 3 eV.
Synthesizing chalcogenide glasses is a delicate process. Measurements and mixing of elements is done at very precise levels. The chalcogenide compounds are reacted in vacuum-sealed fused-silica ampoules at temperatures approaching 1000⁰C for several days. The final step of the process is fast quenching in a liquid coolant in order to preserve the amorphous state.
In this work we describe the synthesis of several binary chalcogenide glasses from the systems Ge-Se and Ge-S. Temperature regimes are presented and discussed within the context of system specific phase diagrams. Images of synthesized glasses are presented and the correlation between appearance, composition and structure are discussed.