非密堆积TiO2空心微球光子晶体的制备与能带分析

Non-close-packed photonic crystal of TiO_2 hollow spheres:Fabrication and photonic bandgap calculation

利用胶体自组装、高温烧结和HF酸刻蚀技术,制备了SiO2微球非密堆积面心立方(FCC)结构的胶体晶体,并以此为模板,利用溶胶凝胶方法和NaOH湿法刻蚀技术制备了TiO2空心微球非密堆积FCC结构光子晶体.利用电子显微镜分析了晶体的结构,用平面波展开法对该结构进行了能带计算与分析.计算结果表明,制备的TiO2空心微球非密堆积FCC结构光子晶体在低能区的第二、第三能带之间除布里渊区的W点仍保持简并外,其余各点简并都已经消除.

We have fabricated the non-close-packed photonic crystals of SiO2 microspheres with the help of the modified vertical method, the thermal sintering technology and etching. The face-centered cubic photonic crystals of TiO2 hollow spheres connected by TiO2 cylindrical tubes have been fabricated using silica template. The structure of the non-close-packed opals was characterized by scanning electron microscopy. We performed photonic band-structure calculations of this structure by a plane wave expansion method. The calculations indicate that the photonic bandgaps at all points of the Brillouin zone in non-close- packed structure were opened except point W.