Temperature sensing of novel Tb3+/Ho3+/Bi3+ co-doped lead-free double perovskite Cs2AgInCl6 nanocrystals

Up to now, the research field of application of lanthanide ions doped lead-free double perovskite Cs2AgInCl6 nanocrystals (NCs) was relatively limited, even less in temperature sensing. Here, Tb3+/Ho3+/Bi3+ ions were successfully doped into Cs2AgInCl6 NCs by hot-injection. The temperature sensing performance of co-doped NCs by using the fluorescence intensity ratio (FIR) was studied through the temperature-dependent emission spectra. By analyzing the influence of ions' doping concentration on temperature sensing performance, the optimal doping concentration of co-doped Cs2AgInCl6 NCs was determined to be 7 % Tb3+, 20 % Ho3+ and 1 % Bi3+. The highest absolute and relative sensitivities reach 1.48 K−1 and 2.48 %/K, respectively. We provide a new doping scheme of lead-free double perovskite NCs which have good temperature sensing performance. This co-doped NCs have great potential application value in non-contact temperature sensing in nanoscale.