Defect-Induced Strain-Tunable Photoluminescence in AgScP$_2$S$_6$

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.