Polycrystalline films of bismuth triiodide are used as beta direct and digital detectors for medical imaging applications. Bismuth(III) iodide is used as an ice nucleant. It is also used in electron microscopy to reveal synapses. Addition of bismuth triiodide has been shown to improve the glass forming ability and thermal stability of Ge-Te-BiI(3) chalcogenide glasses. Solution-processable BiI3 nanosheets have been shown to exhibit the potential to be used as HTLs (Hole Transport Layer) in conventional OPV (organic photovoltaic) devices.