In this work, a novel soft-hard template method towards the direct fabrication of graphene films on silicon/silica substrate is developed via a tri-constituent self-assembly route. Using cetyl trimethyl ammonium bromide (CTAB) as a soft template, silica (SiO2) from tetramethoxysilane as a hard template, and pyrene as a carbon source, the self-assembly process allows the formation of a sandwich-like SiO2/CTAB/pyrene composite, which can be further converted to high quantity graphene films with a thickness of ~1 nm and a size of over 5 μm by thermal treatment. The morphology and thickness of the graphene films can be effectively controlled through the adjustment of the ratio of pyrene to CTAB. Furthermore, a high nonlinear refractive index n2 of ~10−12 m2 W−1 is measured from graphene/silica hybrid film, which is six orders of magnitude larger than that of silicon and comparable to the graphene from chemical vapor deposition process.
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机译：在这项工作中，通过三成分自组装路线，开发了一种新颖的软硬模板方法，用于在硅/二氧化硅衬底上直接制造石墨烯薄膜。使用十六烷基三甲基溴化铵（CTAB）作为软模板，四甲氧基硅烷的二氧化硅（SiO2）作为硬模板，pyr作为碳源，自组装过程允许形成三明治状SiO2 / CTAB / py复合材料可以通过热处理进一步转化为厚约1 nm，尺寸超过5μm的大量石墨烯薄膜。可以通过调节CT与CTAB的比例来有效地控制石墨烯膜的形态和厚度。此外，从石墨烯/二氧化硅杂化膜测得的高非线性折射率n2为〜10 −12 m 2 W -1 ，其为比硅大六个数量级，与化学气相沉积工艺中的石墨烯相当。
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