High stability temperature sensors by CdTe quantum dots encapsulated in SiO₂/PVA hybrids for bearing rotating elements

CdTe quantum dots (QDs) reveal the prospect as temperature sensors for high-speed bearing rotating elements owing to their excellent temperature dependence of photoluminescence (PL) spectra. However, the poor PL peak wavelength stability of CdTe QDs limits its practical application. Herein, we fabricated a CdTe@SiO₂/PVA hybrid film via a sol–gel process based on CdTe QDs. The peak wavelength of PL spectra of the CdTe@SiO₂/PVA hybrid film increases linearly with the rising temperatures, which is similar to CdTe QDs. Significantly, the linear relationship between the peak wavelength of PL spectra of the CdTe@SiO₂/PVA hybrid film and temperature in the heating process from room temperature to 85 °C is consistent with that in the colling process from 85 °C to room temperature. In contrast to CdTe QDs, the CdTe@SiO₂/PVA hybrid film presents superior PL peak wavelength stability. Furthermore, the uniformity of the hybrid film is significantly improved than our previous preparation method of thin films. The excellent film-forming property of the CdTe@SiO₂/PVA hybrids is effective to engineering application. The feasibility and accuracy of the CdTe@SiO₂/PVA sensor are verified through the temperature monitoring test of bearing rotating elements.