Fluorescent Enhancement of Perovskite Nanocrystals by Photonic Crystals

Enhancing the fluorescence of perovskite nanocrystals (PNCs) will not only boost the development of perovskite light-emitting devices (LEDs), but also broaden their applications in various photoelectronic areas. However, an effective approach to flexibly enhance different emission colors with high enhancement factors is still desired. In this work, SiO2 photonic crystals (PCs) are designed to couple with the radiative emission of PNCs. Blue, green, and red fluorescent PNCs emitting at 460, 517 and 620 nm are coated onto PCs with SiO2 particle sizes of 200, 230, and 274 nm, respectively. Fluorescence enhancement factors of 22, 12, and 19 are acquired when the excitation power is 0.078 W. Moreover, the enhancement factor noticeably increases with the excitation power. The enhancement factor for blue PNCs is over 250 with an excitation power of 0.09 W. The enhanced fluorescence of PNCs will facilitate the fluorescence signal acquisition with low noise, which is favorable for optical sensing. As a proof of concept, we demonstrate that the luminescence temperature sensing capability of the PNCs on SiO2 PCs is significantly boosted compared to that of the PNCs on glass.