基于纳米金针尖增强的亚表层光热效应研究  

The Enhanced Photothermal Effect at the Sub-surface of Gold Nanotip

作　　者：方宇欣 陈熠新 岳亚楠[1] FANG Yuxin;CHEN Yixin;YUE Yanan(School of power and mechanical engineering,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学动力与机械学院,武汉430072

出　　处：《工程热物理学报》2023年第5期1323-1329,共7页Journal of Engineering Thermophysics

基　　金：国家自然科学基金项目(No.52076156,No.51576145)。

摘　　要：金纳米针尖激发的光场增强和光热效应在材料表面加工和激光辅助制造方面应用前景广泛,但其能量产生和转化机制的理论分析却鲜见展开。本文通过数值模拟研究了金纳米针尖与光相互作用的光场增强和光热效应。首先研究了独立金针尖的近场增强与入射波长和入射角度的关系。在波长为532 nm的平行光照射下,距离针尖表面10 nm处最大的电场增强高达约66倍。在针尖下方设置硅基底,针尖与硅基底的间隙中出现更强的光场增强,同时在硅基底的亚表层中产生热源。当入射光的功率密度为2×10^(7)W/m^(2)时,该热源的能量密度高达3×10^(15)W/m^(3)。在针尖下方设置单层石墨烯,增强效应形成的纳米尺度热源可以穿透单层碳原子使石墨烯被加热55倍。The optical field enhancement and photothermal effect excited by gold nanotip has broad application prospects in material surface processing and laser-assisted manufacturing,but the theoretical analysis of its energy generation and conversion mechanism is rarely developed.In this paper,numerical simulation is adapted to study the optical field enhancement and photothermal effect of gold nanotip interacting with light.First,the relationship between near-field enhancement of the independent gold tip and the incident wavelength and incident angle is studied.It is varied with incident wavelength and incident angle.Under the irradiation of parallel light with wavelength of 532 nm,the maximum electric field enhancement is as high as 66 times.It occurs in the area 10 nm below the surface of the tip.After adding a silicon substrate under the nanotip,there is a stronger light field enhancement in the gap between the tip and the silicon substrate.At the same time,a heat source is generated in the sub-surface layer of silicon.When the power density of the incident light is 2×10^(7) W/m^(2),the energy density of the heat source is as high as 3×10^(15) W/m^(3).After adding a single-layer graphene under the nanotip,the nanoscale heat source produced by optical enhancement can penetrate the single-layer carbon atoms to heat the graphene by 55 times.

关 键 词：金纳米针尖 光学增强 亚表层 光热效应 

分 类 号：TK114[动力工程及工程热物理—热能工程]