Fabrication and photonic applications of large-domain blue phase films†
Here, a facile method is put forward to fabricate freestanding, large-domain blue phase (BP) films based on self-assembly technology. This fabrication method enables the formation of BP domains with large-scale lateral dimensions of ∼230 μm, which exhibit sharp photonic bandgaps with high reflectivity. In addition, the large-domain BP structures with good optical performances can be preserved after photopolymerization. What is more, the long-range periodic nanostructures of double-twist cylinders can be directly visualized through transmission electron microscopy, providing a powerful tool to investigate BP structures at the nanoscale. Furthermore, dual-wavelength lasing is achieved by doping the large-domain BP films with fluorescent dyes, which is firstly observed in BP materials.