Luminescence Temperature Sensing Using Semiconductor Quantum Dots

The massive size-dependent change in the optical properties of semiconductor quantum dots (QDs), the high luminescence efficiency, and sensitivity of luminescence on temperature, has fostered the application of QDs for chemical, biological, and temperature sensing. This chapter presents the use of temperature-induced changes in emission peak spectral positions, bandwidths, intensities, and emission decays of QDs for temperature monitoring. Ways to obtain dual emissions from QDs, which can be further exploited for ratiometric intensity measurements, are discussed. More details are given on Mn2+ doped QDs, for which two emissions, one from exciton recombination and the other from transition metal ions , are often used for sensitive ratiometric thermometry. Luminescence thermometry examples include both core QDs and heterostructural QDs, those QDs emitting in the visible spectral range and those applicable for near-infrared sensing, as well as relatively novel, low-toxicity QDs. In the majority of the examples the linear and size-dependent sensitivity of luminescence on temperature is highlighted.