Evolution of the structure and properties of solution-based Ge23Sb7S70 thin films during heat treatment

► Chalcogenide films are created through a wet chemical route. ► Residual solvent in spun films degrades IR performance. ► Solvent is removed via a multi-step heat treatment. ► Impact of heat treatment on nano- and micro-scale structure is characterized. ► Infrared spectroscopy and AFM used to characterize films.