Tapping the Light Emitting Potential of Chalcogenide Perovskite SrHfS₃ via Eu²⁺ Doping

Chalcogenide perovskites are an emerging family of perovskite materials, which possess excellent optoelectronic properties comparable with halide perovskites, avoiding the drawbacks of toxicity and poor stability. Due to the superiorities of strong light absorption, direct bandgaps, excellent carrier transport abilities, high defect tolerance, robust stability, and non-toxicity, chalcogenide perovskites have been extensively studied as photovoltaic materials. However, the light emitting potential of chalcogenide perovskites is ignored or less explored. In this work, an Eu2+ doping strategy is proposed to activate the light emitting abilities of chalcogenide perovskite. The synthesized SrHfS3:Eu2+ powder exhibits intense red emission of Eu2+ through the relaxation of 4f(6)5d(1) to 4f(7)5d(0). The strong interband absorption of SrHfS3, as a distinct character of chalcogenide perovskite, harvests the optical energy and funnels it to the luminescent center Eu2+. Besides, SrHfS3:Eu2+ is characterized by superior semiconducting properties, suggesting its strong potential as suitable emitters in light-emitting diodes. Moreover, the obtained SrHfS3:Eu2+ powder and its luminescence properties remain stable under ultraviolet irradiation, water, and high temperature testing. The above observations open a new frontier for exploring luminescent chalcogenide perovskites, highlighting their great potential in lighting and displays, rather than being limited to photovoltaic devices.