Achieving high-precision dual-mode temperature measurement in the photothermal conversion process of SrIn2O4: Er3+, Yb3+ phosphors

Abstract

Accurate measurement of temperature during photothermal conversion is crucial for the application of up-conversion photothermal conversion fluorescent materials. In this paper, a kind of SrIn2O4: Yb3+, Er3+ up-conversion phosphor with strong photothermal conversion ability and high-precision dual-mode temperature measurement performance was synthesized by high-temperature solid-state method. Under 980 nm laser excitation, a high-precision temperature measurement with a maximum relative sensitivity of Sr = 1.2 %K−1 was achieved by using the fluorescence intensity ratio of the thermally coupled energy level pairs (2H11/2/4S3/2) of Er3+ ions. In addition, we found that the luminescent color of the synthesized phosphor can span a large color gamut interval with the rise of temperature, realizing the optical temperature measurement based on temperature-induced color coordinate shift. On this basis, we realized dual-mode temperature monitoring and temperature self-calibration during the photothermal conversion process of SrIn2O4: Yb3+, Er3+ phosphors. These results are of great practical value for the application of photothermal conversion fluorescent materials in micro-zone heating and temperature self-monitoring.