Improvement on fluorescent properties of photonic crystals filled by quantum dots based on multi-layer films

Fluorescence-filled photonic crystal multi-layer films are widely used in laser, sensing, display and other fields due to their photonic bandgap and fluorescence emission properties. In this paper, photonic crystals filled with carbon quantum dots from different precursors have been prepared. It is found that photonic crystals filled with fluorescent carbon quantum dots have optically variable properties excited by ultraviolet light. The optically variable properties of photonic crystals filled with carbon quantum dots at emission peaks of 616, 510 and 450 nm were studied. The fluorescent properties of carbon quantum dots at emission peaks of 616 nm were the best compared to 510 nm and 450 nm. The effects of hole radius R, hole gap d and hole depth h on optically variable properties of fluorescent filled photonic crystals were investigated using 510 nm carbon quantum dots. The results showed that the optically variable properties of fluorescent photonic crystals is strongest when R=400 nm, d=1.5 μm and h=200 nm.