  Metal thiophosphates (MTPs) are a large family of 2D materials that exhibit
large structural and chemical diversity. They also show promise for
applications in energy harvesting and photodetection. Strain and defect
engineering have previously been demonstrated as useful mechanisms to tune
several properties of MTPs such as resistivity, magnetic state, and electronic
band gap. However, the effect of these stimuli on engineering tunable light
emission in MTPs remains unexplored. Here, we show experimentally that
structural defects in metal thiophosphate AgScP$_2$S$_6$ are prominent in
exhibiting photoluminescence, which is likely driven by the
defect-state-to-conduction-band transitions and can be further tuned by
temperature-induced strain gradients.
