Two-layer quantum-dot films show reversible ratiometric temperature sensing

Two-layer polymer films containing different types of quantum dots can serve as reversible ratiometric luminescent temperature sensors, according to a materials study in the Journal of Nanoparticle Research . The researchers prepared and evaluated optically transparent films containing chalcogenide quantum dots alone or both chalcogenide and lead-halide quantum dots. Their luminescence intensity ratios followed predictable mathematical relationships with temperature, and the films retained stable luminescence during repeated heating and cooling cycles.

The investigated design placed different quantum-dot materials in two polymer matrix layers. By varying the mass ratios of the components, the researchers obtained clearly distinguishable individual luminescence peaks in the two-layer films. These separately identifiable peaks supplied the signals used to calculate a luminescence intensity ratio, or LIR, for the different quantum-dot components.

For films containing only chalcogenide quantum dots, the temperature dependence of the LIR was well described by second-order polynomial functions. Across the investigated range of 298–373 K, the reported correlation coefficients for these fits were greater than 0.99. In other words, the measured ratios closely followed the reported mathematical descriptions under the study conditions.

The researchers did not report sensitivity, uncertainty, or response-time values in the available study summary. Films containing both chalcogenide and perovskite quantum dots showed a different response: their LIR had a linear dependence on temperature from 298 to 353 K. That result applies to the specified interval and does not establish that the same relationship continued at higher temperatures. The contrast between the two material combinations indicates that the form of the observed temperature response depended on the quantum-dot composition used in the films.

Repeated heating-and-cooling cycles also revealed temperature stability in the studied films, supporting their use as reusable sensing materials. The available summary does not specify the number of cycles, cycling rate, temperature limits, or the magnitude of any signal changes, so the extent of long-term stability cannot be assessed from it. Overall, the study demonstrates a film-level sensing approach in which temperature is associated with the ratio of separately resolved luminescence signals, with reversible behavior observed under repeated thermal cycling.

Subject of Research: Ratiometric temperature sensing with two-layer quantum-dot-doped polymer films

Article Title: Ratiometric luminescent temperature sensors based on two-layer quantum dot‑doped polymer films

Article References: Sagdeev, D. O., Nizameev, I. R., & Galyametdinov, Y. G. (2026). Ratiometric luminescent temperature sensors based on two-layer quantum dot‑doped polymer films. Journal of Nanoparticle Research, 28(11), Article 276. https://doi.org/10.1007/s11051-026-06797-6

Image Credits: AI Generated

DOI: 10.1007/s11051-026-06797-6

Keywords: quantum dots, temperature sensors, ratiometric luminescence, polymer films, chalcogenide quantum dots, lead-halide quantum dots, perovskite quantum dots, reversible sensing, thermal cycling, Ratiometric, luminescent, temperature