微等离子体射流静电聚焦机理及石墨烯超晶格制备

Graphene superlattices show the excellent characteristics of ultra-high respond, wide spectral coverage, low-power consumption and so on in photodetection, and its core lies in the manufacturing of the periodic hybrid structures. Currently, the main strategy is either patterned graphene functionalization through photolithography or site-selective modification via laser irradiation. However, the former suffers from undesired residues and the latter faces up to low-selectivity of functional groups. Chemical patterning based on the plasma jet technique is widely appealing due to its non-contact, various chemical atmosphere and mask-free features. It’s quite suitable for the fabrication of two-dimensional superlattices such as graphene superlattices, while it suffers from the bottleneck of low-resolution. According to the requirements of patterned graphene functionalization with high resolution, this project will explore a new foucing technique for micro-plasma jet by employing an “electrostatic lens”, to fabricate the high-resolution functional patterns onto pure graphene. The rheological behavior and focusing mechanism of plasma-jet will be studied under the constraint of the electrostatic single lens, and a plasma-jet generator that integrated an “electrostatic lens” will have been designed and fabricated. The stable focusing parameters window and process optimization model of such plasma jet will be established, and they are applied to realize the controlled ignition of specific micro-plasma jet (jet diameter, power intensity). Collaborative optimization of discharging, lens and substrate movement parameters will be applied to control the plasma irradiation spot size and dose at the gas-solid interface, for the preparation of graphene superlattices with high-resolution and high-uniformity fluoride regions. And these superlattices will be integrated into photodetectors to verify their functions. The above researches may provide the theoretical and technological foundation for the high resolution patterning of graphene.

石墨烯超晶格具有超高速、宽光谱、低功耗等优异光电探测特性，其核心在于微纳杂化结构阵列的制造，但光刻工艺存在分子残留，激光直写工艺面临可修饰元素少等不足。等离子体射流工艺可实现石墨烯的非接触式、多化学氛围、直写式图案化改性，是二维超晶格制造的理想技术，但存在分辨率低的瓶颈。本项目针对石墨烯高分辨率图案化改性要求，探索基于“静电透镜”的微等离子体射流聚焦技术，实现石墨烯超晶格杂化结构的高分辨率制造。研究非均匀静电场下等离子体射流的场致流变行为与静电聚焦机制，设计集成“静电透镜”的等离子体射流聚焦喷头，建立射流稳定聚焦的参数窗口与工艺优化模型，实现特定等离子体射流（束径、功率强度）的可控激发；协同优化放电、透镜及基板运动参数，控制等离子体在气固界面的束斑尺寸和辐照程度，用于高分辨率、高均匀一致性氟化石墨烯超晶格制备，并验证其光电探测特性，为石墨烯高分辨率图案化加工提供关键理论与技术支撑。

石墨烯超晶格具有超高速、宽光谱、低功耗等优异光电探测特性，在光电探测、柔性显示和生化传感等领域具有广阔的应用前景，其核心在于微纳杂化结构阵列的制造。等离子体射流工艺可实现石墨烯的非接触式、多化学氛围、直写式图案化改性，是二维超晶格制造的理想技术，但存在分辨率低的瓶颈。本项目针对石墨烯高分辨率图案化改性要求，探索了基于“静电透镜”的微等离子体射流聚焦技术，实现了碳基纳米薄膜高分辨率图案化改性/刻蚀制造。研究了非均匀静电场下等离子体射流的场致流变行为与静电聚焦机制，设计了集成“静电透镜”的等离子体射流聚焦喷头，建立了射流稳定聚焦的参数窗口与工艺优化模型，实现了特定等离子体射流（束径、功率强度）的可控激发；协同优化放电、透镜及基板运动参数，控制了等离子体在气固界面的束斑尺寸和辐照程度，实现了石墨烯等碳基薄膜材料的高分辨率图案化直写改性处理，为大面积柔性微纳结构的高效等离子直写制造与实际应用提供了技术支撑。在Materials Today Physics(IF:10.443)、Small(IF:11.459)、Applied Physics Express(IF:2.772)期刊发表SCI论文3篇，会议优秀论文1篇（ICFDM2020，1/10），接收待发表论文1篇(《航空学报》)；授权中国发明专利4项、受理中国发明专利2项；荣获第十四届设计与制造前沿国际会议优秀论文奖、第五届国际柔性与可拉伸电子学术研讨会暨第五届国际软机械与力学研讨会优秀墙报奖。