Asymmetric dielectric metasurface for fluorescence enhancement of colloidal quantum dots at room temperature

The fluorescence enhancement and manipulation of quantum dots are the research focuses in the field of optics. Metasurfaces have become an important means to enhance the fluorescence emission of quantum dots due to their ability to flexibly control the optical field. This study proposes two metasurfaces, full circular hole arrays and truncated circular hole arrays, which enable precise tuning of characteristic modes via structural parameter optimization, facilitating efficient matching with exciton resonance of the colloidal quantum dots. Through characterizations of angular dispersion reflection and photoluminescence spectra, the correlation between colloidal quantum dots fluorescence enhancement and the metasurface resonant modes is revealed. The fabricated full circular hole array and truncated circular hole array metasurfaces achieve efficient fluorescence enhancement of colloidal quantum dots by factors of 20 and 65 at room temperature, respectively. This study demonstrates that symmetry breaking of metasurfaces can significantly improve the fluorescence enhancement of colloidal quantum dots, providing critical technical support for high-performance quantum dot light-emitting devices.