Improving the luminescence performance of quantum dot-based photonic crystals for white-light emission

A very bright white light is fabricated by combining the advantages of red, green and blue (RGB) QDs with photonic crystal (PC) structures. The results show that the intensity of RGB emission on the PCs can be up to about 8-fold enhanced in comparison to that of the control sample because of the high reflectivity in the UV region of the PC structures, which possess a stopband centered at 366 nm to match an excitation source. Furthermore, the chromaticity coordinates of the RGB film with the PC structure remain almost unchanged, close to pure white light. Introducing the PCs into the white light fabrication process has improved not only the dispersion of QDs due to large surface-to-volume ratios of the inverse opal structures, but also the luminous intensity of the white light resulting from effective light-extraction by the PCs. The approach provides a promising strategy for developing an optical device with high performance.