Abstract
Nano-sized quantum dots (QDs) have the potential for the application of stress sensing materials based on their pressure-sensitive photoluminescence (PL) properties, while the influence of a more realistic loading environment on the PL characteristics of QDs under a high-temperature environment remains to be further studied. Herein, we studied the PL response of CdTe QDs under repetitive loading-unloading conditions under high-temperature coupling to explore the stability of its high temperature stress sensing potential. The results show that the CdTe QDs with size of 3.2 nm can detect pressure in the range of 0-5.4 GPa, and the pressure sensitivity coefficient of PL emission peak energy (EPL) is about 0.054 eV/GPa. Moreover, the relationship between EPL and pressure of CdTe QDs is not sensitive to high temperature and repeated loading, which meets the stability requirements of the sensing function required for stress sensing materials under high temperature. However, the disappearance of PL intensity caused by spontaneous growth as well as the ligand instability of QDs induced by high temperature/high pressure affects the availability of EPL, which has a great influence on the application of CdTe QDs as high-temperature-resistant nano-stress sensing materials. The research provides the mechanical luminescence response mechanism of CdTe QDs under high-temperature/high-pressure coupling conditions, which provides experimental support for the design of high-temperature/high-pressure-resistant QD structures.