Synthesis and fluorescent thermal response of sol-gel SiO2 composite film containing nanodiamonds

Fluorescence of negatively charged nitrogen-vacancy color centers in nanodiamond is applied in nanoscale sensing. Here, we generated a stable transparent composite ND-SiO 2 film by introducing well-dispersed nanodiamonds into silica sol with sol-gel method and spin coating . The transmission electron microscope, X-ray diffraction and Raman curves all can demonstrate homogeneous dispersion of nanodiamond particles in the silicon dioxide film. The hybrid coating displayed significant temperature dependence by studying the fluorescence behavior from liquid nitrogen temperature to room temperature. With rising temperature, the red shift in zero phonon line position, reduction in intensity, extension in the full width at half maximum and decrease in amplitude were obviously typical characteristics. In addition, the sensitivity was 19 K Hz −1/2  at 80K, while it increased to 28 K Hz −1/2  at 300K.