biostudies-literatureUnknown10(33)Cui LThe use of lanthanide luminescence has advanced the field of remote temperature sensing. Luminescence intensity ratio methods relying on emission from two thermally coupled energy levels are popular but suffer from a limited temperature range. Here, we present a versatile luminescent thermometer: Ba(Sr)FBr(Cl):Sm²⁺. The Sm²⁺ ion benefits from multiple thermally coupled excited states to extend the temperature range and has strong parity-allowed 4f⁶→4f⁵5d¹ absorption to increase brightness. We conduct a comparative analysis of the temperature sensing performance of Sm²⁺ in BaFBr, BaFCl, SrFBr, and SrFCl and address the role of concentration, host, and Boltzmann equilibration. Different thermal coupling schemes, ⁵D<Science advanceseado7737https://www.ebi.ac.uk/biostudies/studies/S-EPMC11323894biostudies-literatureHigh-sensitivity luminescent temperature sensors: MFX:1%Sm²⁺ (M = Sr, Ba, X = Cl, Br).PMC11323894Cui LDong ZYu DMeijerink AWang YfalseHigh-sensitivity luminescent temperature sensors: MFX:1%Sm²⁺ (M = Sr, Ba, X = Cl, Br).The use of lanthanide luminescence has advanced the field of remote temperature sensing. Luminescence intensity ratio methods relying on emission from two thermally coupled energy levels are popular but suffer from a limited temperature range. Here, we present a versatile luminescent thermometer: Ba(Sr)FBr(Cl):Sm²⁺. The Sm²⁺ ion benefits from multiple thermally coupled excited states to extend the temperature range and has strong parity-allowed 4f⁶→4f⁵5d¹ absorption to increase brightness. We conduct a comparative analysis of the temperature sensing performance of Sm²⁺ in BaFBr, BaFCl, SrFBr, and SrFCl and address the role of concentration, host, and Boltzmann equilibration. Different thermal coupling schemes, ⁵D<2024-01-01T00:00:00Z2024 Aug2025-04-19T14:50:49.335Z2025-04-19T14:50:49.335ZS-EPMC113238943914172210.1126/sciadv.ado7737